Searching duplicates with (1) after

Hi, I am trying to search for accidental duplicates of files in a folder, but when I search (1) in directory opus, it shows every result with a 1 in it. I'm not computer wizard enough to figure out the language thing that is happening here, whether that be regex or something else. I did try to use two solutions from here from 2008 and 2010, but those do not appear to be working anymore.

Any help? How do I search for all filenames in a folder with (1) contained in the filename or foldername? Alternatively, how do I search for duplicate files?

It should explain what to do when you type the ( character:

Thanks!
I was searching in the top right search field, so I didn't see the tip. Now I found the search menu in tools and everything's okay. One of the tips I mentioned earlier was using '(1') in the search, but it doesn't work in the top right menu so I was just confused. Works fine in the bigger search menu.

The top right search field sends the query to Windows Search. What that does is up to Windows but should be the same as in File Explorer (more or less).