Organize playlists in folders in Music on Mac
To help you organize your songs and music videos, you can create folders, then add playlists and other folders to them. (You can’t add individual songs or videos directly to a folder.)
In the Music app on your Mac, choose File > New > Playlist Folder.
Type a name for the folder and press Return.
To rename a folder, double-click it and type the new name.
To add items to the folder, drag playlists or other folders into the folder.
To move a folder out of another folder, drag it toward the left edge of the Music window.