This is meant for use in DEVONthink.
This will not work with external editors unless you are indexing the files or you export the group to the Finder for use with them.
The groups in DEVONthink don’t exist so there’s no way for external editors to resolve the links, relative or absolute.
And no, item links will not work as they are URL schemes, i.e., they essentially need to be “run”, not just accessed.