As @Ken_Fraleigh stated there is an integration you can bring the stat into Hubitat. Here it is: [RELEASE] Google SDM API - Nest integration
I would recommend ONLY using that within Hubitat. I had it shared out to Homebridge at one point and it was flaky like that if you try to adjust the temp. Sounds like you already have the Homebridge Nest plugin which I also use, and it works great. That is the best way to get it into Homekit.
