If you want to rename the 2 parts of a folder, I would again suggest the absolute path instead of a relative one.
So, use the action you have already created but enter as
Format String: e:\music\%artist%\%album%
You can encapsulate the format string in the function $validate() that removes any illegal character from the path:
Format String: $validate(e:\music\%artist%\%album%,_)
You see that the \ is still a valid character, just as the / is.
So if you want to get rid of these as well, it is a little more complicated:
You can filter for files: you find the input box for filter criteria usually at the bottom of the MP3tag window. If it is not there, press F3 to show it (or press F3 again if you have just hidden the filter input box).
Enter the filter criteria there and you see only the files where the criteria match.
If you want to look up the album name then - if I understood your structure correctly - you do not refer to the parent directory but to the (current) directory. So the filter should be:
"$if($eql($lower(%album%),$lower(%_directory%)),1,0)" IS "0"