To earn the "SAVE HANK" trophy in Detroit: Become Human, you have to make sure to save Hank at the end of the chapter "THE NEST".
Be friendly with Hank at his lunch break, and then investigate the suspect's apartment. Reconstruct his path from the bathroom into the living room and then interact with the chair to start a chase sequence. You need to keep up with the suspect. I tried to keep an equilibrium between safe, risky and balanced options at each opportunity to take different routes. You need to keep up with the quick-time events as they appear as well and just keep pushing forward. When you get to a small field of crops, run straight forward to see Hank grappling with the android. When you get the choice, make sure to save Hank from falling. After the conversation the chapter ends. You'll get the trophy when you reach the flowchart screen.