"The easiest way to find anything on your computer is to use Spotlight," John Carter informs us. "A better way to find something specific is to first go to the top level folder in Finder where you think the file might be, such as 'Dropbox/PMUG Documents,' and put a keyword in the search box of Finder, then select that folder in the tool bar.
The path to the file is shown in the status bar. You don't need to know anything other than how to find something." (Click to enlarge the illustration, then click in the black background to go back to this page.)