A year ago or so, you were able to search a song or artist in your spotify library of playlists and folders, in order to know if a song or artist already at some point were added somewhere in your library.
Spotify should have a function named "Your own library" or something like that, where all your saved songs are shown. And on the top there should be a search function. ("Songs", "Artists" and "Albums" under "Your music" doesn't work that way at all.)
Now when I click a folder all I can see are the playlists it contains, but not the songs. I want to be able to scroll through all my songs in one "window". This was possible a year ago, but now a few updates later it's not even possible to scoll through songs and artists in the folders. All I can see is playlist icons.