Filename - Tag, assign same value to multiple tags

I'd like to know if there is a format syntax to apply the same part of the file name to multiple tags. Take for example %artist% and %albumartist%. For the podcasts I am trying to tag, the artist value only appears once in the path, however I'd like to assign it to both %artist% and %albumartist% at the same time. Is there a way to do that?

No.
But you could create an action group that consists of 2 actions: one to import data from _directory so that some part ends up in ARTIST.
You can then copy the contents of ARTIST into ALBUMARTIST with the next action of the type "Format tag field" for ALBUMARTIST and the format string %artist%.
The process will feel as one action, though.

Actually it's possible with the Guess Values action.
But I think ohrenkino's suggestion is easier.

To get all the tags, that would still be in addition to the use of the Filename - Tag function though, correct? Or are you saying to create an action that parses the entire path and filename thereby duplicating the Filename - Tag function?

Either way.
If you have already run the Converter and ARTIST is filled then it is sufficienct to apply only the action that copies the contents of ARTIST into the field ALBUMARTIST.

If you have not yet filled ARTIST but want to fill the two fields with one mouse-click then you need the action group with the two actions (extract, then copy) in which the extraction-action sort of re-enacts the converter.