Sonos doesn’t change the data presented by the streaming services. If you want to sort or filter, you need to do that work on each service, not within the Sonos app itself. Sonos only allows filtering / sorting of playlists that are generated within Sonos itself. 

I can sort playlists in other apps, but the Sonos app ignores that sorting. For example, if I sort alphabetically in Qobuz, and then switch to Sonos, the playlists appear sorted from newest to oldest in Sonos.
 

Is there really no way to change this, or to search or filter playlists in Sonos? Doesn’t seem like a lot to ask…