Hi,
A simple filter by categories should do the trick here.
I would suggest the following configuration (or similar):
– Choose to display all categories in the filter (or some of them), anc change their display mode to drop-down: https://i.imgur.com/uVhAOTV.png
– Also, turning off this option may help as well: https://i.imgur.com/Za3q9L9.png
That should filter the results by category, and only display those that have that category registered, no missing results either.