The OS X Finder is an amazing thing, letting you create folder within folder, duplicate files, find your documents, and generally get stuff done. More and more, the Finder features are being integrated across all apps and documents on your Mac.
Case in point is the ability to find the directory path of a document from the document’s title bar, as well as being able to (since Mountain Lion, anyway) rename your documents in the title bar as well. All of this is thanks to the proxy icon, which Apple defines as: “An icon in the title bar of a document window that users can manipulate as if they were manipulating the corresponding file-system object.”
Here’s how to use them on your Mac.
If you’re using an app with a proxy icon, like Text Edit, Pages, Preview, or others, you can figure out where in the folder hierarchy that file is with a simple Command-click to the proxy icon itself. If you choose a folder higher in the structure, you’ll open the Finder to that folder, letting you mess with it there. This can also be helpful when you’re trying to remember where you actually saved a file.
In addition, since OS X Mountain Lion, you can click on the proxy icon and get a contextual menu. Choose Rename… to type in a new file name for your document, right in the title bar itself. Pretty slick, if you ask me.
Now you don’t have to quit an app, then pop out to the Finder to rename a file you’re working on, and you can always check where you’ve stored a document you’re in the middle of editing.
Via: Stack Exchange