Playlist Cross Reference

Select any number of playlists, right click and select Tools ➡ Cross Reference to find out which tracks multiple playlists have in common.

You can find out which tracks both playlists have (e.g. you might want to know which tracks are in both your "House" playlist and in your "Top 100" playlist).

You can also find out which tracks are missing from the selected playlists. This will cross reference the selected playlists with the entire library and create a new playlist with any track that is not found in the selected playlists. Be careful as this may create a very large playlist.