I have a Vault 2 and I don’t know, but my guess is you have to do it through a PC or Mac with the Vault being on your network. Pretty sure you can’t do it through your phone or an iPad/tablet which is all I use. I’ve only copied one CD twice so I’ll be interested in someone responding how to do this too.
Google is your friend. When I did a search on "Bluesound Vault 2 delete album" it says you have to do it from a computer on the same network. It linked to this article:
After you have deleted the tracks from the network database, using your PC or Mac, you have to go to the bluesound app and rebuild the index.
To rebuild the index, from the bluesound app:
To see the progress of the rebuilding: Settings/Music Library - 3rd line “Indexing“ Will show you the progress of the rebuild.