For this you must complete all sector challenges across RDA and Na'vi.
List of zones:
Blue Lagoon
Needle Hills
FEBA
Graves Bog
Hanging Gardens
Iknimaya
Swotulu
Va'era Ramunong
Kxania Taw
Toruka Na'ring
Plains of Goliath
Note: Blue Lagoon and Plains of Goliath only need to be completed once on either faction, you do not need to complete the zones twice. However, if the trophy does not pop and you have completed all the zones then do these zones on both factions. I've not heard that happened to anybody though.