The diff / meld command is not magic. Just “meld /path/to/file/one /path/to/file/two”. Try this with any other files. Make a copy of some file, modify a bit, then diff. In other words “meld file-from-source-folder file-on-system”. Figure out the paths. Just go into any folder in the source code folder and look around.
Just try if you got the right folders.
Once you’re sure about the full file paths, you can compare them using meld.
Since this thread is about an apparmor-profile-sdwdate issue, forget about apparmor-profile-torbrowser. Work with the apparmor-profile-sdwdate folder.