Relative path in action

Is there a way for an Action format string to access the track's relative (to current dir) folderpath?

%folderpath_rel% returns null. Computing it using the current directory needs a placeholder I cannot find.

Thanks.

Computing it using the current directory needs a placeholder I cannot find.

I since found (perhaps since added)

https://docs.mp3tag.de/format/#export
%_workingpath% Path of current working directory