At the bottom of the Directories window is a Last Directory
pushbutton which is labeled with the current number of directories in the
active tree. Pushing this button will cause a switch to the previous directory
used in the active File window.
Two levels of directories are initially read by FS/2. As you use directories, additional levels will be added to the tree. If you wish to know the total number of directories on a drive, perform a Query on the root directory of the desired volume, or select the Read All Dirs option from the Directory menu. The number of directories displayed has no brackets if it represents less than the total number of directories. There will be square brackets displayed if the drive read was for all directories.
Clicking with the RMB on the Last Directory pushbutton will popup the Frequent Use Directories (Freq Dir) menu.