All of your Google Wifi points are connected to each other wirelessly using 802.11s. As long as they are within range, they can communicate with one another without going through a router. This allows for a faster, more efficient routing of data.
I just wanted to jump in real fast to see if you saw Edward's reply and to see if you still needed some help on this or if you were able to get it sorted out. If you are still needing some help, just let us know and we'll be happy to continue helping.
Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.