For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
This would include events from the time Primo is captured in the woods until he arrives in Auschwitz and is stripped of his clothing, his name, and everything he thought to be true about life.
Act II
Primo "adjusts" to life in Auschwitz, and observes the way in which daily life becomes a constant struggle to survive. He develops strategies to make it through each day and hang onto his humanity.
Act III
The Germans abandon the camp and the remaining prisoners have to rely on themselves to stay alive until the Russians arrive. Finally, the camp is liberated and Primo returns home.