The same idea as mine was posted in 2012 by @ryeguy_24 and labeled as "not right now" in 2017. If Spotify has not forgotten about this gem of a discovery functionality by now, then you can just kindly ignore this idea and give the 2012 one an upvote.
Sometimes you find a playlist, you recognize a few songs and you know immediately it is going to be good.
Similarly, finding playlists that contain artists you really like is a very efficient way of finding more artists that you might love.
So, it would be fantastic to add an extra box for searching playlists where you can put the names/artists of some songs you want to have included in the playlists that show up in the search result.
Updated on 2019-07-23
As you mentioned, a similar Idea has also been suggested, and only one thread can exist per idea:
If possible, vote for it, and add a comment there, so it may be considered. Any update on the matter should be posted there.
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