When grouping movies from sets, these movies should appear in the search results, not only the movie set

For example, if the three movies from the “Dark Knight Collection” are grouped in the set, and the option “Group movies from sets” is enabled, then NO search results for “Batman” when doing a search in the main search menu (top right) at the “Movies” main screen, even if one of the movies is “Batman begins”

Well this is not a search function more a filter function hence the result. It filter what is on screen.
If you want a search you need to use the search button in the left menu.

I can ensure that the set will be visible if the filter match a movie from the set but it will never list the actual movies when you group movies from sets.