Use Part of Foldername in Filename

[StarGeek]

Ah, I didn't catch that bitonals was below 31822000473199.  In that case, you can use the tag Filepath to get the absolute file path, then grab what you need with some regex, though that gets messy.

Try this:
exiftool "-documentname<${filepath;s/^.*\/(.*?)(?:\/[^\/]+){2}$/$1/}/$filename" -ext tif -overwrite_original .\bitonals\

Though this will fail if you try to recurse into subdirectories below bitonals.