How do I delete albums with the Bluesound OS app

I have a Bluesound Node 2i. I have a NAS drive. When I delete my CD's from the NAS, they do not delete from the Bluesound App. I replaced a lot of CD's that I converted with Apple Music to using DB Power Amp for better conversions. I now have duplicates of everything in Bluesound. I would like to delete these files. Thanks