They post it in the patch notes when they update it. For 3.2:

[2.0][3.0] As of patch 3.2, the following duties count towards high-level full party duty achievements:
The Bowl of Embers (Extreme) / The Navel (Extreme) / The Howling Eye (Extreme) / Thornmarch (Extreme) / The Whorleater (Extreme) / The Striking Tree (Extreme) / Akh Afah Amphitheatre (Extreme) / Thok ast Thok (Extreme) / The Limitless Blue (Extreme) / The Minstrel's Ballad: Thordan's Reign / Containment Bay S1T7 (Extreme) / The Binding Coil of Bahamut (excluding turn 3) / The Second Coil of Bahamut / The Second Coil of Bahamut (Savage) / The Final Coil of Bahamut / Alexander: Gordias / Alexander: Gordias (Savage) / Alexander: Midas / Alexander: Midas (Savage)