This is not a Qubes-specific question. Qubes GUI is xfce (or, KDE, if you install it manually). For xfce I found this: two windows side-by-side and tile, cascade: possible in Xfce? / General discussion / Xfce Forums.
You would have to enter the path somewhere anyway. Why not enter it after you open the terminal as cd path/to/directory?
There are a lot of tips and tricks in the documentation. For example: