how can i move my tank turret separately from its body?

ok so im trying to make a tank TPS and i have done the movement stuff and the camera stuff i learn from fps shooter. the problem is in fps your body and head move together, what i want is that my tank head can rotate when i move the camera with my mouse while the body rotate with A and D key.

Make a root node - parent the turret to the root node - parent the body of the tank to the root node.
Parent the camera to the turret.
Transform the root node to move the tank body.
Parent the turret rotation to mouse input. Parent the body rotation/movement to the A and D keys.