Collision object Under Character Controller?

Is it possible to check if an object is colliding specifically with the bottom of the character controller?

I want to store the object in a variable that the character is standing on. I don't want this to apply if the character is colliding with any other part(eg. sides or top).

You can override the function OnControllerColliderHit(hit : ControllerColliderHit) and check hit.moveDirection and hit.normal. They will indicate the direction of the character and the direction of the force the character encounters.

Another option: CharacterController.collisionFlags is updated every time you call CharacterController.Move. You could check if collisionFlags == CollisionFlags.Below.