One can look up the ETOPS rule for the aircraft they’re flying and then select for that rule using Great Circle Mapper. (The areas shaded in darker blue are restricted because, in this case, they’d not be allowed under ETOPS 180 rules.) 787s come with ETOPS 330 “out of the box”, as long as they are properly equipped, crewed and maintained, though certain Rolls Royce engined 787s were limited to ETOPS 140. (I flew on Aloha’s 737-200 ETOPS aircraft, a bit of an odd aircraft for ETOPS but necessary for some longer overwater flights, when I flew to / from Midway / MDY.)
ETOPS 180 on EZE-SYD
ETOPS 330 on same route