Include Mac System Files in OS X Searches with a Simple Adjustment

How to Search System Files in MacOS X

This trick to search system files on a Mac applies to all versions of MacOS, including Mojave:

1. Go to the Finder if you haven’t done so already and start a new file search (hit Command+F or go to Find from the File menu)
2. Type the search query for a system file into a Finder window search as usual
   
3. Click the plus (+) button to add additional search parameters
   
4. Click the “Kind” menu and choose “Other”
   
5. At the attribute selection box, type “System” and choose the “System files” attribute, then click “OK”
   
6. Now click the next search parameter for “aren’t included” and select “are included” instead
   
7. Find the searched for system file(s) as intended