Sometimes I want to use UCX on Mac OS to investigate system files. Normally those are in hidden directories. The Open File dialogs by default do not show hidden directories or files. I seem to remember that there is a way to show hidden files, but I can no longer find it.
UltraCompare for Mac: How to display hidden files?
UltraCompare for Mac: How to display hidden files?
I don't have a Mac. But second link output by my favorite www search engine on searching for Mac open hidden file referenced: How to Hide Files and View Hidden Files on Mac OS X. The description in View Hidden Files and Folders in the Open/Dialog looks promising in my point of view taking into account that hidden files and directories on Mac and Linux are just files/directories of which name start with a dot. By the way: The first page on search results list is: How to Show Hidden Files and Folders on a Mac: 11 Steps
Best regards from an UC/UE/UES for Windows user from Austria