Prenyltransferase that catalyzes the transfer of the geranylgeranyl moiety of geranylgeranyl diphosphate (GGPP) to the C2 hydroxyl of (S)-3-O-geranylgeranylglyceryl phosphate (GGGP). This reaction is the second ether-bond-formation step in the biosynthesis of archaeal membrane lipids. (2E,6E,10E)-geranylgeranyl diphosphate + sn-3-O-(geranylgeranyl)glycerol 1-phosphate = 2,3-bis-O-(geranylgeranyl)-sn-glycerol 1-phosphate + diphosphate Membrane lipid metabolism; glycerophospholipid metabolism. Belongs to the UbiA prenyltransferase family. DGGGP synthase subfamily.