The earliest this can be done is Chapter 3. As
Reqqu pointed out in the comments, Chapter 3 can be selected from the start of the game without having to complete the other two.
This achievement requires you to revisit the area where the events of the final mission of Chapter 2 took place. It is near the eastern edge of the map located north of Witchrock.
Visual of the area, placing in spoiler tags in case you want to experience it in-game for yourself: