Find missing files in Xcode

If you have a bunch of missing (red) files that now live in the same directory, you can improve on the "fix each path individually in the inspector" method by selecting (Cmd-click) all the files at once. You'll see "multiple values" in the inspector, like so:

Clicking the button under the Location dropdown will bring up a directory selector -- note that the prompt says "Choose folder containing..." rather than "Choose file and location".

As far as I know, Xcode doesn't have a way to automatically locate moved files. You can reconnect a reference to its file using the Inspector (panel on the right) but it is somewhat tedious to do so. In your case, it would probably be faster to simply delete the references and then add the files back to your project.