Searching across downloaded playlists

[j2intel]

Hi,

I have several downloaded playlists and there doesn't seem to be a way to search offline for a particular artist or song throughout them. Other than going through and saving each and every song individually to "my library", is there easier way to do this? This wasn't an issue with google play music.

Also if there was a way to play multiple playlists together, that would be amazing.

Thanks.