Hi, I recently just got my second hub to cover a blind spot in my house. It works fine until I realize you can't add two Hubitat hubs to one Google Home account. The HubConnect setup seems too complicated for me, so I come up with a solution that doesn't require HubConnect. I know it's been a long time but this thread is still on top of the search results, so I thought it may still be helpful to share my setup here.
All you need is Hubitat's Hub Mesh function, a built-in app called Mirror, and a powerline Ethernet Adapter if the second hub is too far away from the Router.
Let's say Hub1 is connected to google home and the Bedroom_Switch is connected to Hub2. Our goal is to control Bedroom_Switch by google home. Below are the steps.
Step 1: Share Bedroom_Switch on Hub2 using the Hub Mesh. This will create a virtual switch on Hub1 called Bedroom_Switch_on_Hub2, which will mirror the behavior of Bedroom_Switch.
Step 2: Create a virtual switch on Hub1 called Bedroom_Switch_Virtual. Then on Hub1, use the build-in app "Mirror", let Bedroom_Switch_on_Hub2 be the source switch and Bedroom_Switch_Virtual be the slave switch. That way, Bedroom_Switch_virtual will mirror the behavior of Bedroom_Switch_on_Hub2.
Step 3: Share Bedroom_Switch_Virtual on Hub1 using Hub Mesh. Then a virtual device called Bedroom_Switch_Virtual_on_Hub1 will be created on Hub2, which mirrors Bedroom_Switch_Virtual.
Step 4: On Hub2, use the app "Mirror" and let Bedroom_Switch mirror the behavior of Bedroom_Switch_Virtual_on_Hub1.
It may sound complicated because of my lengthy explanation (forgive me about my English I'm not a native speaker), but it's really not. Essentially, we created a loop of four devices, each of which always mirrors its previous one. That way, Bedroom_Switch and Bedroom_Switch_Virtual are identical. Now Bedroom_Switch_Virtual is available on Google Home and can be used to control Bedroom_Switch.
Finally, I need to emphasize the importance of the Powerline Ethernet Adapter. If the second Hubitat Hub is too far away from the Router that you can't connect it with an Ethernet cable, there are solutions that can be found Anyone Using Hubitat Connected via WiFi?. However, the Hub Mesh doesn't work with the universal wireless adaptor. The hubs cannot find each other on the network. But Powerline DOES work! The Powerline technique uses the electric wire in the wall as the cable, so it works almost the same as the wired connection.
I hope that helps!