Nest thermostat installation to furnace and heat pump
Thermostat User's Guide, pg 168, Fig. 160



Here is the wiring for 1 stage heat with aux heat and emergency heat from the Nest E Pro Installation Guide



I don't think you're compatible with the Nest E since you have separate controls for both auxiliary heat and emergency heat. A Nest Learning Thermostat would be compatible:



If you had a Nest Learning Thermostat, you would wire:


G -> G
W -> W2/AUX
R -> Rc
X -> * (Emergency Heat)
B -> C
O -> O/B
Y -> Y1