Will depend on how your folder names are named.
Could be as simple as this:
.

1:Regex -> Simple
%1 is everything up to the first space
%2 is everything after the first space
& you simply flip them around
12:Filters - Folders
your source path would be, Z:\
Note that as written (displayed in the shot), the last item, "Record Drawings" is being incorrectly renamed (based on what you've described, 'YYYY<sp>Jethro Tull Thick As A Brick'.
But if all of your folders are named as I've described:
YYYY<sp>Jethro Tull Thick As A Brick
YYYY<sp>Tangerine Dream
YYYY<sp>,Boris Kova? & LaDaABa Orchestra
you should be OK.
(But verify first

.)