In shimmer desktop for instance.
The filter aren't removed when I right click on filter-button.
Or may be I misunderstand ?

I think it works, it works for me at least. It only concerns the playlist filter, not any other filter. The Filter widget displays an icon indicating the current playlist : one for when using no filter (=> whole library is the playlist), one for a static list, and one for a filtered list. When right clicking on it you should get back to the whole-library icon if it was showing another icon.

Ah ok. I was thinking this button affect all filters.