Navigate to a folder called (0)
The (0) is not part of the path. I'm not sure what it is, to be honest 

I tried that terminal command and for me it says:

Screen 1 (space 1):

(14)/Users/joonaspaakko/Documents/uDesktop NEXT Library/Catalog/uDNature7658.jpg

Screen 2 (space 1):

(19)/Users/joonaspaakko/Documents/uDesktop NEXT Library/Catalog/uDNature7658.jpg

Screen 1 (space 2):

(3)/Users/joonaspaakko/Documents/uDesktop NEXT Library/Catalog/uDNature7408.jpg

Screen 2 (space 2):

(9)/Users/joonaspaakko/Documents/uDesktop NEXT Library/Catalog/uDNature7408.jpg

etc....



When I navigate to the path ignoring the parenthesis and the number, I get to the folder with the wallpaper, which in my case is: /Users/joonaspaakko/Documents/uDesktop NEXT Library/Catalog/

So based on that I would say your wallpaper is in /Library/. You can get there easily with the Go to Folder..., but in case you are not aware, that is the global Library folder you can find, if you go to Machintosh HD