If one uses indexing for the DT database, while putting the full files in a normal Finder folder, it is possible for DT to get confused if the data base and/or folder of originals is moved. It “must be” easy to tell DT where to look to reestablish ALL of the links. I assume it should still be easy if both the database and folder are copied to another machine.
Unfortunately, I’ve not found the trick. It’s probably in front of my nose.???
I believe this has been suggested here in the past. To reduce complexity (e.g., avoid the overhead of managing symlinks in the background), I believe user intervention is needed. The approach taken by Adobe Lightroom (and others) is to provide a “locate” menu action to enable the user to tell the app where the missing file/folder is.
Click the document or folder with broken links, choose “locate” from the menu, Finder opens - navigate to the new location, select the new location, links are restored to the extent possible.
This tells the app where to re-establish the root of the path. Works across volumes. If subgroups with broken links exist on the same path, then they are re-linked at the same time. Might need intelligence to avoid indexing/importing documents on that path that were not indexed/imported before and eliminate database documents that disappeared from the moved folders.
Let’s say the documents were in the folder /A/B/C and are now in the folder /D/E. Then you could create an alias C in the folder /A/B pointing to /D/E.