Action to rename artist folder

I'm just starting to use mp3tag and I like it! My music directories look like this:

D:\Music\Alanis Morissette\Jagged Little Pill Acoustic\01 - All I Really Want.mp3

I want to create an action that will rename the artist to what is shown in the Album Artist column of mp3tag. I found this but still don't understand setting up the action:

format artist:
$regexp(%_folderpath%,.+\(.+)\(.+)\,$1)

It is not quite clear to me: do you want to copy the contents of the field ALBUMARTIST to the field ARTIST?
Then use an action of the type "Format value" for ARTIST
Format string: %albumartist%

You can achieve the same with the function Convert>Tag-Tag for ARTIST,
Format string: %albumartist%

Or do you want to extract the string from the parent directory?
The it would be easiest to use the function COnvert>Filename-Tag
Pattern: %artist%\%dummy%\%dummy%

No I'm wanting to rename the artist folder to match what is listed in the album artist column

Then use an action of the type "Format value" for _DIRECTORY
Format string: D:\Music\%albumartist%\%album%
(or as alternative the function Convert>Tag-Tag - that has a preview so it may be easier to see what may be the outcome.)