To set up your Elite Pro 2 + SuperAmp for Xbox One for use with a Mac computer, please do the following.
First, plug the mic into the headset. To do so, make sure the keyed parts of the mic boom and mic jack line up, and then gently plug the mic in until you hear a click.
Then, plug the headset into the SuperAmp with the included cable. Make sure the end of the cable with the "Connect This End to Headset" is the side that is plugged into the headset; the other side will need to be plugged into the port on the SuperAmp with the headset icon next to it.
Make sure to fully insert the cable into the jack on the headset. It is a snug fit, and you should feel the plug slide into place twice. The cable is not fully inserted/plugged in until the plug slides into place the second time. An easy way to check if your headset cable is plugged in all the way is to make sure that the headset and mic icons (located on the headset and mic boom, respectively) are lined up with each other.
Then, plug the Mini-USB end of the included USB Cable into the SuperAmp, and plug the USB end of the same cable into a USB Port on your Mac, as shown below.
Then, set the SuperAmp to PC Mode in the mobile version of the Turtle Beach Audio Hub (available here for Android and iOS).
Open System Preferences, and then click on "Sound" to open the Sound Settings.
In the Input tab, select "Elite SuperAmp PC".
In the Output tab, select "Elite SuperAmp PC".
You are now ready to use your Elite Pro 2 + SuperAmp for Xbox One headset with a Mac!