BeatDrop 2 - Spotify-like Song & Mod Manager - BeastSaber
Any song that you add to your "favorites" gets saved to a "favorites" playlist. You can rename this playlist file as the playlist name you want. Any songs after that will be added to a new "Favorites" playlist
Any song that you bookmark on bsaber will be added to a playlist file once SyncSaber runs. You can use this to create playlists. SyncSaber will also create playlists for a lot of different types of lists like the CuratorRecommended songs, the Top PP maps, Top Trending, etc.
An alternative to BeatDrop to create playlists
Create playlists from Spotify or Youtube
Beat Saber Custom Playlist Compiler