Problems when filtering conditional content with DITA

Hi

I try to build conditional content for example for different target audiences. I have used DITAVAL and I'm able to exclude content when saving the book with fm components (which is good). But when I try to take this further and use another options like background color to highlight the conditioned parts (would be nice for review) but this doesn't work.

See the example of one of my test ditaval files. I have tried to use different selections (for example flag) but nothing happens. Is there an error or is this function just not working?

I have tried also the filter by attribute but not any success there. I have understood that it works only on topic level, is that true? Don't like that option as there you must change the settings on topic level after review (always a place for user errors).

I have 2019 version.