Nighthawk Guest Network Limitation

Nighthawk R7000

Firmware Version 
V1.0.9.18_1.2.27

I wanted to set up some IP cameras and other devices on a guest network that wouldn't have access to my actual local network. However, it seems like my only option is to "Let devices see each other and allow access to my local network." I need them to be able to see each other to work, but I don't want them to have access to my local network. 

I've gotta be missing something because this kind of kills a lot of the advantages one would hope to get when using a guest network. As it is, it's not really a "Guest Network."