I don't honestly know if you can navigate to your user library from there on a Mac (I can go anywhere on Windows that I have permissions to see, as long as I have show hidden files eanbled), but deleting the InDesign Defaults file will restore the location to the default in your user library, at the cost of losing other customizations.
I think for safety you might want to make a copy of the InDesign Defaults file as it is before making the change so you can overwrite a new one in the future if you need to.