Make the groups reflect their file system path instead of being a path relative to the project root. Now if you right click "inspector" and Add File, Xcode will automatically show the file picker for the Source/JavaScriptCore/inspector file system path, instead of Source/JavaScriptCore. Likewise for the subfolder groups ("remote", "scripts").
Created attachment 219128 [details] [PATCH] Proposed Fix
Landed r160558: <http://trac.webkit.org/changeset/160558>