Add water and steamer rack to pressure cooker. Fashion a piece of aluminum foil into a pan with this shallow sides. Place asparagus in foil pan and place on steamer rack.
Place garlic and butter around asparagus. Close and lock lid, set pressure cooker to "steam/veggies", and press "start/stop".
When done, quick release and make sure all pressure has been released before opening lid.
Carefully open lid and remove asparagus to serving platter. Pour melted butter and garlic over asparagus. Top with juice from one lemon and Parmesan cheese. Season with salt and pepper.