Show project path in Xcode windows
As with most Mac OS X windows, Command-click on the title will show you the path.
As of Yosemite the closest thing to control-clicking the title bar (which is no longer possible) is to right-click the file name in the jump menu at the top of your project window in Xcode.
I work on multiple copies of the same project at the same time, and it's really annoying to try to remember which window is which.
I have the same problem, I use the file inspector to see the full path