What a terrible idea! That’s a classic example of how to make people sick in VR. Never move VR players or override the HMD camera!!! You make people vomit in your game. You should be forced to play your camera movement in VR yourself!
However - with no-VR you can add classic camera movement by the mouse X and Y axis. Just add pitch input from mouse Y and add yaw input from mouse X.
If you have a controller you can tick “Use Controller Rotation Pitch” in the camera. Otherwise you can directly place the Mouse events in the BP. If your camera doesn’t belong to a pawn you can also make a rotator from pitch and yaw and feed that into a set relative rotation node.
And never animate/move the VR camera. You’ll regret this.