Hey LordHorusNL,
This is a bit trickier but in most cases based on direction we must use the Transform Direction action. We want to know where Forward is and forward is always +1 on Z.
So we have the touchpad axis first. Then we use the transform direction, and I set it up to move forward based on where I am looking, so for the game object, I set it to Camera (head). In local direction I set the X and Y to 0 and Z to 1. I then stored the Vector 3 result.
Next we Get Vector 3 XYZ (action) from our new vector 3 variable and store the X (headset x) and Z (headset z). Now I use Get Vector2 XY and store the Y (axis Y). I use the float multiply action to multiply headset Z by axis Y (so that if not touching the touchpad it will be at 0 therefore multiplying any value to 0 so the only movements that occur are when the touchpad is pressed). I then multiply headset X and by axis Y. Now we create a new Vector 3 (headset) and set the X to headset x and Z to headset Z (I also set the Y to zero so that it will always be zero). And I used translate to move the headset, I set the game object to Camera Rig and Vector to my new headset variable. Now any direction I look, and I press down on the touchpad y it will move forward in that direction.
That will move your character, if you would also like to use the X on touchpad axis, you would do the same steps but now add the two vector3's at the end together and place that new variable in translate. I would suggest testing out different methods of movement to see what works best for you.
I hope this helps! If you have any questions, please let me know!