Print in your phone all values, Tilt is only when you move your phone to see up-down, X and Z is used X = 0 see sky, X = ±3 see floor.
Gravity in X detect when you rotate your phone left and right, like in temple run game.
To look around is hard… cuz i dont see a value to detect this but i think in use gravity or rotation rate.
Try with this.
And remember, “Set Actor Rotation” use a rotation… a new rotation is a vector with values between {-1,1} to indicate direction, first get actual rotation of your camera, with this vector, based on the values of Tilt or another, add in X,Y or Z of actual rotation vector some values based on tilt, scale this value, if tilt value is between {0, ±3}, generate a rule to get values between {-0.25,0.25} this can be more or less, to control speed, and add into actual camera rotation vector. Finally add this vector to move your camera. Enjoy!
Regards!