That lever number 5 is the one that adjusts the tilt angle. You need both levers 2 and 5 to raise or lower the seat maintaining the same angle. The lever 5 is very stiff, sometimes it needs to be pushed to both directions to get it going. If it's totally loose or stuck and does nothing, ask the dealer to fix it. It's almost as important as the lever 2 to get the seating position right. I just hope the steering wheel would come further out, I want to keep my legs quite straight which sets the seat farther than for most people as tall as me.
8Y is definitely not the easiest car to get in and out.