Every week one map is selected for the Trials of Osiris mode and will not change at all during the entire weekend until Bungie resets the wee on Tuesday. So it is the same map all weekend and doesn't change.   Go Flawless Across 4 Different Maps triumph will take at least four weeks to complete. Keep track of every time you go flawlessly and what map it is. Every map has different areas to test your skill like sniping lanes, positions, and advantages, so take some time understanding the level before hopping into Trials. Understanding the map and different rotations players will make is a huge benefit.