Tweak Spotlight in Finder to search system files

You may have found that Spotlight does not search through system files (ie. your Library folder). However, there is a way to search your system files using Spotlight from the Finder. After beginning your search in Spotlight, the trick is to  select “Show All” files to open a Finder window with that search. Then, click the “+” button in the top right of the window’s search bar and select “other…” from the left-most pulldown menu. In the sheet that opens you can search for and enable the “System Files” option and choose to keep it in the smart search menu.