If I’m getting the gist of your question, you want to create a selection-based filter (e.g. elements) and then, later on, be able to add a rule-based filter (e.g. category) to that selection-based filter. In other words, you don’t want to add/remove elements to/from the selection-based filter set the way the tool works.
No can do, Pieter...kind of...
The workaround is to create a rule-based category selection method, and then put in some filter rules to include or exclude certain elements based on parameters (i.e. include all walls that have the same “Function” like the OOTB “Interior”).
Other than that, these are two different functioning tools; kind of like hiding in view by element or by category. But, I suspect you already knew that, and were just looking for confirmation.
P.S. Betcha an App or Dynamo could do this. mmm...I wonder?
