When you dig down through folder within folder within folder to find a file, there are a variety of ways to navigate back up through those layers of folders. The most obvious is to click the Previous arrow in the top left of the Finder window.
A hidden method which lets you jump directly to any of the folders “above” the one you’re in, is to Control+Click (or Command+Click, or right-click) the Finder window’s title bar. Up pops a list of the enclosing folders, and you can click any of the folders in that hierarchy to jump directly to the chosen location. If you prefer to use the keyboard, press Command+Up-Arrow to head back up the folder hierarchy – each press of Command+Up-Arrow will take you to the next higher enclosing folder.
Previous vs. Enclosing
There is, of course, a difference between using this ‘up the folder hierarchy” technique and using Previous in the Finder window. The Previous arrow navigates back through the locations you’ve been viewing, and not directly up the folder hierarchy. Using Previous lets you return by the path you followed to get to your current location, no matter how circuitous that path. Using the enclosing folder technique ignores the path you took to get to the current folder and heads by the most direct route directly up through the folder hierarchy.
For example, if you view your Documents folder, then the Desktop, then the Applications folder and then head back into Documents and down into Accounts, clicking the Previous Arrow will take you from the Accounts folder back through:
Documents -> Applications -> Desktop -> Documents
On the other hand, repeatedly pressing Command+Up-Arrow will take you from Accounts to:
Documents -> user folder -> Users -> Macintosh HD -> Mac