AC1750 Connect to Wireless AP

In the router setup if I go to Advanced > Administration > Wireless AP it looks like I can connect the router to a another network wirelessly. The help on that page says,

"View the wireless access points (APs) that are broadcasting wireless networks in your area. For each wireless network, the security level and the signal strength are displayed. To join a network, select it and enter its password if prompted."

However, I cannot seem to select a network. Clicking on a listed network does nothing. Is there something I'm missing? I have a newer moidem/router combo so I was hoping to use this one to get a better signal on the other side of the house and plug some devices directly into it (like a network bridge).

Is what I am looking to do possible with the C6300?

If not, what is that area of the the setup supposed to do?