I think I have answered my own question. For future reference for others:
Going back to the documentation I did some more digging and found more info in the (Dutch) helpfiles:
-> When you do a search for instance on $FFwfJob.jobName$ (like I was doing) will get you to a single page, without a way to see that there are sibling pages, or being able to click to the parent page. This threw me off a little.
One of the pages is this one: http://localhost/FreeFlowCore/Help/nl/wwhelp/wwhimpl/js/html/wwhelp.htm#href=MAX.html
Here file and folder name are specified.
$FFFolder Name$ is the one I was after.
I am running into an issue while trying to access Folder name and File Name of a MAX file in one of my workflows.
The filename I access as follows: $FFwfJob.fileName$
I use that one for file based on the variable name I found in the documentation (Dutch). I have not found the same for Folder name in the documentation, so I started experimenting a bit. I have tried these:
$FFwfJob.folderName$: just a best guess based on fileName variable
$FFMapnaam$: based on the label next to the MAX standard fieldname in the hotfolder configuration.
$FFFolder name$: based on the column name i the header row of the MAX file I'm using
All these are picked up by core, appending a succes status to the row of the MAX file, but return an error in core stating (translated from dutch): An error occurred while evaluating the expression: 'Folder name'. (replace 'Folder name' with whatever variable name I was trying)
Creating a custom MAX field results in an error processing the MAX file. The following status is appended to the MAX file row:
File access error - at least one file not found.
What is the correct variable name for accessing the Folder name field?
(Is there more extensive documentation on more of these variable names, the Dutch documentation seems limited on this? I'm happy to use English documentation. In fact, I would prefer it.)