In order to make sure at least the back symbol is present (there is no point in opening the link to see where the directory) actually goes, it will be worth adding the following code at line 3413 in DDgui_FileDialog% :
IF num_dir%=0 AND num_file%=0
DIMPUSH files$[],".."
num_dir%=1
ENDIF
This will let people access the directory, and go back.