DARQ: Complete Edition

In chapter 3, once you have placed all of the severed arms into their slots and they pull the levers, it will open up the ground to your right which leads to the exit. Instead of going down there, turn around and use the device in the center to rotate the level twice, or 180 degrees. Now go left into the newly opened hole mentioned before and the journal page is right next to the exit.

If you are going back and collecting any journals you missed with chapter select, you do not have to finish the level to save it. You can immediately quit to the menu / choose a new chapter after picking it up.