Try looking here :-
https://store.google.com/us/category/nest_thermostats?hl=en-US#thermostat_compatibility
https://support.google.com/googlenes...ith-two-labels
I replaced my Hive thermostat that was bloody horrid with a Honeywell T6R, I however only had live, neutral, earth, common and heating on to deal with as I just have a combi.