Controller button to navigate in Vuforia

It depends on how you want it to work. If you want the controls to work relative to the model's orientation, you'll need to add some math transforms to make it work. You should be able to use standard 3D transformation matrices to convert the button presses into translations in the model's coordinate system instead of the universal one.

If you want the controls to always function relative to the user, no matter what their orientation or location, you'll also need to add some math transforms to make it work, but you'll want to target the user's coordinate system instead of the model's. @RolandRaytchev has some good posts about how to determine the user/camera location via Javascript, and then you could use translate relative to the user's coordinate system instead of the universal one.