"Can I (or can you) connect the category filter with the tag filter in a way that only the tags are displays that are used by this category."
Could you please update to the newest version (4.0.7). There are new options for Tag Filtering:
Screen Shot 2021-12-04 at 7.51.16 AM.png
You can hide tags too!
Screen Shot 2021-12-04 at 7.53.07 AM.png
Best wishes Thomas π Richard"https://laytheme.com/version-history.html"