I agree with Paul.
If you want to go up a directory, click on the directory you want in the window above. In the picture you posted, you could click on "Local Disk (C)."

The forward and back buttons work like they do in a browser. If you open an new browser window, neither of those buttons function until you click on a link or type a new URL. Then the back button is active. If you use it, the forward button will become active.