Actually the filter widget is pretty limited and it’s only possible to show long list of all picked taxonomies (it doesn’t look nice). Will be nice to have an option to pick a [select toggle].
Will be great to hide part of taxonomies which are empty.
I have a project where I need to use filters. I will take a look in the next week and see if I can get it working. I personally prefer FacetWP more as it does not use jquery unlike WPGridBuilder and the libraries are much smaller too.