In Compass 1.21.2, using a map filter (Draw a polygon, Draw a circle) overwrites existing filters.
For example, using the sample_restaurants dataset, click one of the cuisine values to set the filer for that cuisine
{cuisine: 'American'}. Then expand the address field and draw a circle or polygon on the map. The cuisine filter gets overwritten with by the $geoWithin. This is a regression from earlier version of Compass.