Music Library: 'Split Apart' option not there?

They are. It goes back to my ‘Various Artists’ problem in the other thread.
These are ten albums in separate folders named “Café del Mar Vol 1”, “Café del Mar Vol 2”, etc…
Oddly. for the 2nd time now, Vol 9 & 10 got merged?
And they are even separated in the details of the album since Vol 9 & 10 appear as separate discs.

Anyway, I solved it another way by simply selecting the files of Vol 10, clicking the pencil tool and renaming the Album field with “…Vol. 10”.

But I know yesterday I had done it using the ‘Split Apart’ function…strange.