You can add InputAxis in ProjectSettings->Input. Add a new one, call it e.g. “VerticalMov” and add two inputs. One for Left-Trigger and one for Right-Trigger. Give one the multiplier 1 and the other one -1. Then in your blueprint add an InputEvent (right click and search for “VerticalMov” or what ever you called it) and multiply it’s axis value by the vector you want to move it (e.g. x = 0, y = 0, z = 5). Add these result as “AddRelativeLocation” to your Actor/Camera. This will move the camera every frame 5 units up/down (depending on the button you pressed).
Hope that helped! 