I doubt the developer will fix this. The development history says:
[2012-07-19] REL: VERSION 2.52 (for Windows XP/2003/Vista/2008/7)
[2012-07-19] NEW: added option to specify default directory for cover art.
[2012-07-19] NEW: added preferences page for directories used in Mp3tag.
So you can use a place-holders like the examples below:
%_directory% Name of the parent directory
%_folderpath% Path without file name
%_folderpath_rel% Folderpath relative to Export output file if output and track files are on same drive, else absolute
%_parent_directory% Name of the grandparent folder
%_path% File name with path
%_volume% Volume label
%_workingdir% Name of current working directory
%_workingpath% Path of current working directory
Hmmm. Or at least I thought you could. I tried changing it to %_volume% and %_parent_directory% but it brings me to the %_folderpath% everytime.
Anyone else have this problem?