Identifying UNIQUE set of files

I need to find UNIQUE set of files across a specified set of multiple locations (either drive letters or folder paths). In short, if the file occurs ONLY at ONE of the locations provided without being present at any of the other locations, I need to identify these files. This is to ensure that I back them up as soon as possible.

I need to use this to find files that are not available in my backup sets across multiple locations.

Duplicate finder only finds duplicate files across multiple locations and not the other way around.

Folder synchronization finds missing files but it does not accept more than two locations at a time and hence cannot be used to find unique files across more than two sets of locations.

Any idea on how to achieve this using Directory Opus (9.1.3) will be greatly appreciated.

Thanking in advance,

Edou

Maybe someone else will have an idea but I can't think of a good way to do this.

I think I would end up doing the Duplicate Search and then saving the results into a .CSV text file (which the Tools -> Print Folder can do), then do a Find to get a list of all of the files and get that into a .CSV as well. Then I'd use Excel or something to remove all the filepaths in the duplicates list from the full list, leaving only the unique ones...

...Which is a bit convoluted but the best I can think of.