The Library screen in the Music app on Apple TV includes any Apple Music content and playlists you added, your iTunes Store purchases and playlists, and music synced from your computer, iPhone, or iPad if you have an Apple Music or iTunes Match subscription.
To learn more about syncing your library, see the Apple Support article to sort or filter your playlists. Select a playlist to see more information or to start playing it.
Artists: Shows all the artists in your library. Select an artist to see all the songs and albums by that artist in your library, select or or or select Add to a Playlist.
Navigate to the Now Playing screen, Use Sync Library with your Apple Music subscription.