Drag the GameplayCamera component to the Event Graph to create a node.
Drag from the GameplayCamera component node and search for then select Get Initial Variable Table.
Drag from the Return Value pin of the Get Initial Variable Table node and search for then select Set Camera Rig Parameters .
Find your Camera Asset and the Camera Rig that has the Camera Rig Parameter exposed.
Thats how updating variable for a Rig works.
