[Chadfrom308]

You would have to take the drive stick value and either scale it to the Z slider value from the joystick, or limit it at the joystick.

If you want to scale it (like if the Z slider was at 70% and the joystick was at 90%, the output would be 63%), take the joystick input and multiply it by the Z input.

If you want to limit it (like if the Z slider was at 70% and the joystick was at 90%, the output would be 70%), take the joystick input and do a greater than block and wire the boolean output to the boolean input on a select function block. After that, route the Z axis into the true input and the joystick axis to the false input

After you have either of those, you have to add a couple of logic statements for going in reverse (Because -z axis * - joystick axis = positive number, driving the robot in the opposite direction)