I use this system:
First I add CD1, CD2, etc in the Comment field. You could also make a custom tag for CD numbers.
Album tag is always the plain album name.
Then I rename files from properties (MC Library Tool) like this:
\Music\Artist\Album\CD1 - Track # - Name.xyz
\Music\Artist\Album\CD2 - Track # - Name.xyz
or for various artists albums:
\Music\Album\CD 1 - Track # - Artist - Name.xyz
\Music\Album\CD 2 - Track # - Artist - Name.xyz
I don't keep unnecessary information in the filenames if the folder path already includes that information.
I like to keep the original track numbers in the filenames, because after renaming the files I fill track numbers from list order. (MC Library Tool)
If I have:
Album X, CD 1, 15 tracks
Album X, CD 2, 12 tracks
Album X, CD 3, 18 tracks
They become:
Album X, 45 tracks
Comment field still includes CD numbers and if I ever need original track numbers I can find them in the filenames.