You may know that you can expand and collapse Finder folders in a tree view using the left and right arrow keys. But did you know that you can expand or collapse all of the root-level folders at once? It's a cool trick that can save you a lot of time when navigating your Mac's files. With the Finder window focused (click anywhere inside the file view), just type Command-A to select all, then use the left or right arrow to collapse or expand all of the folders simultaneously. Neat, right?
You can also expand a folder recursively (expand all of its child folders) by selecting it and holding down the Option key when you click the triangle next to it (or press the right arrow key when the folder is selected). This works in reverse for collapsing, to
