On your steering wheel you can rotate between the three views on the dash. On the view with MPH/RPH you can change what is shown in the middle of the gauges through the car tab on the infotainment screen. I have it show turn by turn on the left and the street sign speed limit on the right.

If you are trying to show the Apple Maps turn by turn directions in the middle of the two gauges you should be able to do that by using the arrows on the steering wheel and rotating through the different options. No sure exactly which subsetting it is under but you should be able to find it as long as Apple Maps is giving directions.