The invention provides a controller and an actuator for mounting to a controller, enables a user with access to a plurality (two or more) of control functions from a single actuator. In particular, the present disclosure provides an actuator which in normal use is hidden from view for example, but not limited to, by being mounted to the rear of a controller. It is therefore desirable that the actuator can be readily found by touch and that the user can readily find a desired control function. The actuator comprises a plurality of distinct or distinguishable degrees of freedom of movement, when mounted to the controller, the actuator requires specific actuation gestures, manipulations or actions to activate a desired one of a plurality of control functions associated with the actuator.