If you mean Sonos playlists that feature was removed in the new app as other features were deemed more important in the first phase. 
 

”Playlist editing” (whatever that exactly means) may be restored in a December release according to this article:

https://support.sonos.com/en/article/the-new-sonos-app-and-future-feature-updates

You can still create and edit playlists on the Mac Sonos app. Don’t know about Windows but I suspect it’s the same. 
It should return to the phone/tablet app next month…