Well... That option doesn't exist. (at least, not that i know of, let's see if mouser surprises us
But... You can navigate in farr to the directory you are and type the search.
Imagine you're in 'c:\programs\findandrun\' and you want to file 'FindAndRunRobotSystemTrayTrigger.exe'.
You can type in farr:
and it'll find that file.