This groups songs by their Album Artist and Album field and finds cases where the songs are matched to different MusicBrainz albums.
Here we see we have two folders representing each disc, and each disc has been matched to a different version of the correct album. This can be easily resolved by using the Match to One Album task to force a match to the same album version. Again this album was not shown for split folders because each folder is consistently matched but when grouped by Album Artist and Album metadata.
