diff --git a/.gitmodules b/.gitmodules
index 771ed3fc6bf54..7028b79fbe7b1 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,7 +1,7 @@
 [submodule "themes/docsy"]
 	path = themes/docsy
 	url = https://github.com/google/docsy.git
-	branch = v0.2.0
+	branch = v0.3.0
 [submodule "api-ref-generator"]
 	path = api-ref-generator
 	url = https://github.com/kubernetes-sigs/reference-docs
diff --git a/hugo.toml b/hugo.toml
index 13ba477cc9414..b0fde0b773f28 100644
--- a/hugo.toml
+++ b/hugo.toml
@@ -218,6 +218,8 @@ url = "https://v1-27.docs.kubernetes.io"
 [params.ui]
 # Enable to show the side bar menu in its compact state.
 sidebar_menu_compact = false
+# Show this many levels in compact mode
+ul_show = 3
 # Show expand/collapse icon for sidebar sections.
 sidebar_menu_foldable = true
 # https://github.com/gohugoio/hugo/issues/8918#issuecomment-903314696
diff --git a/layouts/partials/sidebar-tree.html b/layouts/partials/sidebar-tree.html
index f8ce9b468e7ff..ae6f622df611c 100644
--- a/layouts/partials/sidebar-tree.html
+++ b/layouts/partials/sidebar-tree.html
@@ -1,36 +1,35 @@
-{{/* We cache this partial for bigger sites and set the active class client side. */}}
-{{ $sidebarCacheLimit := cond (isset .Site.Params.ui "sidebar_cache_limit") .Site.Params.ui.sidebar_cache_limit 2000 -}}
-{{ $shouldDelayActive := ge (len .Site.Pages) $sidebarCacheLimit -}}
+{{/* Always cache this partial; set the active class client side. */}}
+{{ $shouldDelayActive := true }}
 <div id="td-sidebar-menu" class="td-sidebar__inner{{ if $shouldDelayActive }} d-none{{ end }}">
   {{ if not .Site.Params.ui.sidebar_search_disable -}}
   <form class="td-sidebar__search d-flex align-items-center">
     {{ partial "search-input.html" . }}
-    <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-docs-nav" aria-expanded="false" aria-label="Toggle section navigation">
+    <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-section-nav" aria-expanded="false" aria-label="Toggle section navigation">
     </button>
   </form>
   {{ else -}}
   <div id="content-mobile">
   <form class="td-sidebar__search d-flex align-items-center">
     {{ partial "search-input.html" . }}
-    <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-docs-nav" aria-expanded="false" aria-label="Toggle section navigation">
+    <button class="btn btn-link td-sidebar__toggle d-md-none p-0 ml-3 fas fa-bars" type="button" data-toggle="collapse" data-target="#td-section-nav" aria-controls="td-section-nav" aria-expanded="false" aria-label="Toggle section navigation">
     </button>
   </form>
   </div>
   <div id="content-desktop"></div>
   {{ end -}}
   <nav class="collapse td-sidebar-nav{{ if .Site.Params.ui.sidebar_menu_foldable }} foldable-nav{{ end }}" id="td-section-nav">
-    <!-- {{ if  (gt (len .Site.Home.Translations) 0) }}
+    {{- if (and false (gt (len .Site.Home.Translations) 0) ) -}}
     <div class="nav-item dropdown d-block d-lg-none">
       {{ partial "navbar-lang-selector.html" . }}
     </div>
-    {{ end }} -->
-    <!-- {{ $navRoot := cond (and (ne .Params.toc_root true) (eq .Site.Home.Type "docs")) .Site.Home .FirstSection }} -->
+    {{ end -}}
+    {{ $navRoot := cond (and (ne .Params.toc_root true) (eq .Site.Home.Type "docs")) .Site.Home .FirstSection -}}
     {{ $ulNr := 0 -}}
     {{ $ulShow := cond (isset .Site.Params.ui "ul_show") .Site.Params.ui.ul_show 1 -}}
     {{ $sidebarMenuTruncate := cond (isset .Site.Params.ui "sidebar_menu_truncate") .Site.Params.ui.sidebar_menu_truncate 50 -}}
-    {{ $currentLang := .Site.Language -}}
+    {{ $currentLang := string .Site.Language -}}
     <ul class="td-sidebar-nav__section pr-md-3 ul-{{ $ulNr }}">
-      {{ template "section-tree-nav-section" (dict "page" . "section" .FirstSection "shouldDelayActive" $shouldDelayActive "sidebarMenuTruncate" $sidebarMenuTruncate "ulNr" $ulNr "ulShow" (add $ulShow 1) "currentLang" $currentLang)  }}
+      {{ template "section-tree-nav-section" (dict "page" . "section" $navRoot "shouldDelayActive" $shouldDelayActive "sidebarMenuTruncate" $sidebarMenuTruncate "ulNr" $ulNr "ulShow" (add $ulShow 1) "currentLang" $currentLang) }}
     </ul>
   </nav>
 </div>
@@ -42,9 +41,10 @@
   {{ $treeRoot := cond (eq .ulNr 0) true false -}}
   {{ $ulNr := .ulNr -}}
   {{ $ulShow := .ulShow -}}
+  {{ $currentLang := .currentLang -}}
   {{ $active := and (not $shouldDelayActive) (eq $s $p) -}}
   {{ $activePath := and (not $shouldDelayActive) ($p.IsDescendant $s) -}}
-  {{ $show := cond (or (lt $ulNr $ulShow) $activePath (and (not $shouldDelayActive) (eq $s.Parent $p.Parent)) (and (not $shouldDelayActive) (eq $s.Parent $p)) (and (not $shouldDelayActive) ($p.IsDescendant $s.Parent))) true false -}}
+  {{ $show := cond (or (lt $ulNr $ulShow) $activePath (and (not $shouldDelayActive) (eq $s.Parent $p.Parent)) (and (not $shouldDelayActive) (eq $s.Parent $p)) (not $p.Site.Params.ui.sidebar_menu_compact) (and (not $shouldDelayActive) ($p.IsDescendant $s.Parent))) true false -}}
   {{ $mid := printf "m-%s" ($s.RelPermalink | anchorize) -}}
   {{ $pages_tmp := where (union $s.Pages $s.Sections).ByWeight ".Params.toc_hide" "!=" true -}}
   {{/* We get untranslated subpages below to make sure we build all levels of the sidenav in localizationed docs sets */}}
@@ -60,44 +60,26 @@
   {{ $withChild := gt (len $pages) 0 -}}
   {{ $manualLink := cond (isset $s.Params "manuallink") $s.Params.manualLink ( cond (isset $s.Params "manuallinkrelref") (relref $s $s.Params.manualLinkRelref) $s.RelPermalink) -}}
   {{ $manualLinkTitle := cond (isset $s.Params "manuallinktitle") $s.Params.manualLinkTitle $s.Title -}}
-
+  {{ $isForeignLanguage := (ne (string $s.Lang) ($.currentLang)) -}}
   <li class="td-sidebar-nav__section-title td-sidebar-nav__section{{ if $withChild }} with-child{{ else }} without-child{{ end }}{{ if $activePath }} active-path{{ end }}{{ if (not (or $show $p.Site.Params.ui.sidebar_menu_foldable )) }} collapse{{ end }}" id="{{ $mid }}-li">
     {{ if (and $p.Site.Params.ui.sidebar_menu_foldable (ge $ulNr 1)) -}}
-      <input type="checkbox" id="{{ $mid }}-check"{{ if $activePath}} checked{{ end }}/>
-      <label for="{{ $mid }}-check"><a href="{{ $manualLink }}"{{ if ne $s.LinkTitle $manualLinkTitle }} title="{{ $manualLinkTitle }}"{{ end }}{{ with $s.Params.manualLinkTarget }} target="{{ . }}"{{ if eq . "_blank" }} rel="noopener"{{ end }}{{ end }} class="align-left pl-0 {{ if $active}} active{{ end }} td-sidebar-link{{ if $s.IsPage }} td-sidebar-link__page{{ else }} td-sidebar-link__section{{ end }}{{ if $treeRoot }} tree-root{{ end }}" id="{{ $mid }}">{{ with $s.Params.Icon}}<i class="{{ . }}"></i>{{ end }}<span class="{{ if $active }}td-sidebar-nav-active-item{{ end }}">{{ $s.LinkTitle }}</span></a></label>
+    <input type="checkbox" id="{{ $mid }}-check"{{ if $activePath}} checked{{ end }}/>
+    <label for="{{ $mid }}-check"><a href="{{ $manualLink }}"{{ if ne $s.LinkTitle $manualLinkTitle }} title="{{ $manualLinkTitle }}"{{ end }}{{ with $s.Params.manualLinkTarget }} target="{{ . }}"{{ if eq . "_blank" }} rel="noopener"{{ end }}{{ end }} class="align-left pl-0 {{ if $active}} active{{ end }} td-sidebar-link{{ if $s.IsPage }} td-sidebar-link__page{{ else }} td-sidebar-link__section{{ end }}{{ if $treeRoot }} tree-root{{ end }}" id="{{ $mid }}">{{ with $s.Params.Icon}}<i class="{{ . }}"></i>{{ end }}<span class="{{ if $active }}td-sidebar-nav-active-item{{ end }}">{{ $s.LinkTitle }}</span>{{ if $isForeignLanguage }} <small title="{{ T (printf "i18n_language_name_long_%s" $s.Lang ) }}">({{ $s.Lang | upper }})</small>{{ end -}}</a></label>
     {{ else -}}
-      {{ if not $treeRoot }}
-      <a href="{{ $manualLink }}"{{ if ne $s.LinkTitle $manualLinkTitle }} title="{{ $manualLinkTitle }}"{{ end }}{{ with $s.Params.manualLinkTarget }} target="{{ . }}"{{ if eq . "_blank" }} rel="noopener"{{ end }}{{ end }} class="align-left pl-0{{ if $active}} active{{ end }} td-sidebar-link{{ if $s.IsPage }} td-sidebar-link__page{{ else }} td-sidebar-link__section{{ end }}" id="{{ $mid }}">{{ with $s.Params.Icon}}<i class="{{ . }}"></i>{{ end }}<span class="{{ if $active }}td-sidebar-nav-active-item{{ end }}">{{ $s.LinkTitle }}</span></a>
-      {{ end -}}
-    {{ end -}}
-    {{ if $withChild -}}
-      {{ $ulNr := add $ulNr 1 -}}
-      <ul class="ul-{{ $ulNr }}{{ if (gt $ulNr 1)}} foldable{{end}}">
-        {{ $pages := where (union $s.Pages $s.Sections).ByWeight ".Params.toc_hide" "!=" true -}}
-        {{ with site.Params.language_alternatives -}}
-          {{ range . }}
-            {{ with (where $.section.Translations ".Lang" . ) -}}
-              {{ $p := index . 0 -}}
-              {{ $pages = where ( $pages | lang.Merge (union $p.Pages $p.Sections)) ".Params.toc_hide" "!=" true -}}
-            {{ end -}}
-          {{ end -}}
-        {{ end -}}
-        {{ $pages := $pages | first 50 -}}
-        {{ range $pages -}}
-          {{ if (not (and (eq $s $p.Site.Home) (eq .Params.toc_root true)) ) -}}
-            {{ $mid := printf "m-%s" (.RelPermalink | anchorize) -}}
-            {{ $active := eq . $p -}}
-            {{ $isForeignLanguage := (ne (string .Lang) (string $.currentLang)) -}}
-            {{ if (and $isForeignLanguage  ($p.IsDescendant $s)) -}}
-              <a class="td-sidebar-link td-sidebar-link__page {{ if and (not $shouldDelayActive) $active }} active{{ end }}" id="{{ $mid }}" {{ if $isForeignLanguage }}target="_blank"{{ end }}  href="{{ .RelPermalink }}">
-                {{ .LinkTitle }}{{ if $isForeignLanguage }} <small>({{ .Lang | upper }})</small>{{ end -}}
-              </a>
-            {{ else -}}
-              {{ template "section-tree-nav-section" (dict "page" $p "section" . "currentLang" $.currentLang "shouldDelayActive" $shouldDelayActive "sidebarMenuTruncate" $sidebarMenuTruncate "ulNr" $ulNr "ulShow" $ulShow) }}
-            {{- end }}
-          {{- end }}
-        {{- end }}
-      </ul>
+    {{ if not $treeRoot }}
+    <a href="{{ $manualLink }}"{{ if ne $s.LinkTitle $manualLinkTitle }} title="{{ $manualLinkTitle }}"{{ end }}{{ with $s.Params.manualLinkTarget }} target="{{ . }}"{{ if eq . "_blank" }} rel="noopener"{{ end }}{{ end }} class="align-left pl-0{{ if $active}} active{{ end }} td-sidebar-link{{ if $s.IsPage }} td-sidebar-link__page{{ else }} td-sidebar-link__section{{ end }}{{ if $treeRoot }} tree-root{{ end }}" id="{{ $mid }}">{{ with $s.Params.Icon}}<i class="{{ . }}"></i>{{ end }}<span class="{{ if $active }}td-sidebar-nav-active-item{{ end }}">{{ $s.LinkTitle }}</span>{{ if $isForeignLanguage }} <small title="{{ T (printf "i18n_language_name_long_%s" $s.Lang ) }}">({{ $s.Lang | upper }})</small>{{ end -}}</a>
+    {{- end }}
+    {{- end }}
+    {{- if $withChild }}
+    {{- $ulNr := add $ulNr 1 }}
+    <ul class="ul-{{ $ulNr }}{{ if (gt $ulNr 1)}} foldable{{end}}">
+      {{ range $pages -}}
+      {{ $mid := printf "m-%s" (.RelPermalink | anchorize) -}}
+      {{ if (not (and (eq $s $p.Site.Home) (eq .Params.toc_root true))) -}}
+      {{ template "section-tree-nav-section" (dict "page" $p "section" . "shouldDelayActive" $shouldDelayActive "sidebarMenuTruncate" $sidebarMenuTruncate "ulNr" $ulNr "ulShow" $ulShow "currentLang" $currentLang) }}
+      {{- end }}
+      {{- end }}
+    </ul>
     {{- end }}
   </li>
-{{- end }}
+{{- end }}
\ No newline at end of file
diff --git a/themes/docsy b/themes/docsy
index 1c77bb2448394..9f55cf34808d7 160000
--- a/themes/docsy
+++ b/themes/docsy
@@ -1 +1 @@
-Subproject commit 1c77bb24483946f11c13f882f836a940b55ad019
+Subproject commit 9f55cf34808d720bcfff9398c9f9bb7fd8fce4ec