You can save any filter as a “smart” playlist.
A smart playlist doesn’t store the library items, but just the filter criteria.
Which means the smart playlist is auto-updating itself, whenever you add or remove items which fit the filter criteria.
You can also store them as smart Collections instead of playlists. Which is probably the better choice.
Playlists are for playing things one after another.
But in this case you probably won’t do that.
