I am an Assessment Intern in a Tier 2 firm. I was a callback intern and now I am an assessment intern. I am getting work directly from the partners. Now, I'm nearing the end of my Assessment Internship. What can I expect? How does it go from here? How do I bring up the discussion for a PPO?

Try to ask for feedback from senior associates/partners, identify if there is one particular team that you're working very closely with(in case you've been taking work from multiple teams). Typically as someone who has been in a similar position, I tried to bring this up for discussion during a break or during the end of the day, so you're not disturbing them during work. They must have already discussed internally regarding your performance and everything, so just try to go and talk to the nicest person in your opinion. Hope you get the offer! :')