If you want to do it completely automatically, then save the name of the original folder in a user-defined field like
%mypath% formatted with %_folderpath%.
To distribute the files to new folders, use Converter>Tag-Filename with
Format string: %album%\%_filename%
To get them all back again into the original folder, use Converter>Tag-Tag for _DIRECTORY with an absolute path like
Format string: d:\mymusic\Soundtracks\ABCD
enter here the original path of the album or re-use the contents of %mypath% if you have saved it.
This moves all selected files to the named folder and removes the extra folders that were created to renumber the files.