(DOCSP-5112): Boolean filter updates (#172)

* (DOCSP-5112): Boolean filter updates

* Minor tweak

* Updates per Ravind's feedback

Author: jeff-allen-mongo

source/filter-documents.txt

@@ -48,6 +48,8 @@ options. You can filter fields with the following data types:
 
 - :ref:`Date <filter-date>`
 
+- :ref:`Boolean <filter-boolean>`
+
 .. note::
 
    You cannot use the same field for multiple filters.
@@ -237,6 +239,39 @@ To define an upper bound for your absolute date filter:
 
    The date and time formats used in your bounds depend
    on your location, as determined from your browser settings.
+ 
+
+.. _filter-boolean:
+
+Filter Boolean Fields
+~~~~~~~~~~~~~~~~~~~~~
+
+You can filter the chart data based on the boolean value of a specific
+field. Drag a boolean field to the filter panel to view the available
+options:
+
+- :guilabel:`True` displays documents where the field value is ``true``.
+
+- :guilabel:`False` displays documents where the field value is
+  ``false``.
+
+- :guilabel:`NULL / MISSING` displays documents where the field is
+  ``null`` or does not exist.
+
+All options are selected by default. The chart preview updates as you
+modify the selected options. Deselecting all options renders a blank
+chart.
+
+.. example::
+
+   A chart using the following filter only displays documents where the
+   ``passed`` field is ``true``. The chart does not display documents
+   where the ``passed`` field is ``false``, ``null``, or does not
+   exist.
+
+   .. figure:: /images/charts/boolean-filter.png
+      :scale: 60%
+      :alt: Image showing boolean filter
 
 .. _query-bar: