It is already possible to do an advanced search in spotify, but not in your own playlists. I would like to be able to an advanced search in playlists because I have a big playlist and my music taste fluctuates quite a bit. There are times when I solely want to listen to rock, and just simply filtering it out would be very handy.
Updated on 2019-03-09
Hey and thanks for your contribution!
A similar idea has also been suggested here
Add your vote and comments in support there please : )