If the cradle is symetrical, then the hangar is mounted at the midpoint of the base. If, however, you have included a vertical support on one end to support the gun stock and prevent its tipping (useful if measuring over/unders and repeaters), then it is better to adjust the position of the hangar slightly.
The goal is for the hangar to be mounted at the cradle's balance point so that the pendulum, when empty, hangs level.
Do not worry if it is not perfect, the bubble level is set to "level" when the device is setup.
