Before a controller will target anything, you must setup a few things and specify a transform of an object to aim. Here are the options available in the inspector tab of a controller component:

Target – A transform of an object the controller will aim at

Body – Specifies the transform of the vertical tracking component along the elevation plane

Mount – Specifies the transform of the horizontal tracking component along the heading plane

Heading tracking speed – The rate at which the component can rotate towards target on the horizontal plane

Elevation tracking speed – The rate at which the component can pivot towards target in the vertical plane

Heading limit – The arc of fire along the horizontal plane. The editor gizmo marked with red

Elevation limit – The arc of fire along the vertical plane.  The editor gizmo marked with blue

Debug draw – Whether to draw a debug line between the swivel center and the far end point