In many apps on the Mac, including the Microsoft Office apps, it can be initially confusing to try to save a file in a folder outside of the default folders. When viewing the save dialog, you will see the familiar fields for naming the file and choosing the format, and you will see a drop-down list labeled WHERE.
When you click the WHERE drop-down list, you will see options that include folders saved as favorites in the sidebar of a Finder window and any other folders to which you’ve recently saved. However, if you need a folder that isn’t in this list, it isn’t immediately clear how they can be accessed.
The trick is to expand the save dialog view by clicking the triangle button to the right of the SAVE AS field.
Clicking this triangle button expands the save dialog and shows a full file browser where the WHERE drop-down list used to be. This new view includes everything from the shortcuts bar on the left to the view choice buttons along the top, and everything else you would see in a full Finder window. It even includes a Spotlight search field. Now it is easy to find whatever folder you’d like in order to save your file.
Each application also remembers whether you last had this save dialog expanded or compacted, and will open that way the next time you go to save a file. So you don’t need to click this triangle each time you save a file, just the first time. This memory is limited to each application though, so, for example, if you’ve already expanded the view in Word, you will still need to do so when you save a file in Excel.
Jason Merrill, Mac & iOS Consultant