Best way to tag album & album set titles in multidisc sets?

I am wondering how best to set up album & set titles for multi-disc sets in tags that will work nicely with LMS.

I find it straight forward and logical to handle this by folder path in my file system - I have a bottom-level folder per disc and give it a parent folders if it is part of a multidisc set. For example:

Eagles\[1975] One of these nights\
Eagles\The Studio Albums 1972-1979\[1972] Eagles\
Eagles\The Studio Albums 1972-1979\[1973] Desperado\
Eagles\The Studio Albums 1972-1979\[1974] On the border\[1974] On the border CD1-2\
Eagles\The Studio Albums 1972-1979\[1974] On the border\[1974] On the border CD2-2\
Eagles\The Studio Albums 1972-1979\[1975] One of these nights\

... etc. In this example I have shown two copies of One of these nights, one in the box-set, one acquired separately. I've fictitiously made "On the border" a double CD to illustrate how I handle it, i.e. each disk gets two parent folders. flac files are only ever contained the bottom folder of each path.


I am, however, stuck as how to do it with tags as there is no hierarchical system for handling album titles, just the "Album" tag, as far as I know. I could use this "Album" tag thus:

"The Studio Albums 1972-1979: [1973] Desperado"

... but this is a bit ungainly when browsing LMS.

Ideally I would create and use a tag called "AlbumSetTitle" or somesuch for the set title, e.g. "The Studio Albums 1972-1979", keeping the "Album" tag for disc title, e.g. "[1973] Desperado". However, although I can create tags (in mp3tag), as far as I can see (and I have Googled around a bit), LMS cannot use it for browsing/searching - do please correct me if I am wrong!

Any suggestion welcome, thank you.