mrb1982 has it correct and it will work. In order for the bubble to be between the lines the barrel has to be either pointing at the ground or at the moon.
PS: I don't like the level near the turrets because it interferes with my fingers while turning the turret in front of it. I see you can swing it away, but it gives you one more thing to worry about when you should be concentrating on your shot.
The small level was removed after the offset level on the scope tube was installed. I am able to look through the scope with my right eye while looking at the offset bubble with my left eye. And before you ask the action is right handed and is a duel port.