Cobb is going to use operation Mr. Charles, where he tells Robert he's in a dream. Wait, isn't that the exact opposite of what they wanted to have happen?
It seems to work. He convincesĀ Robert that he (Cobb) is there to help him escape the extractors (which are actually the subconscious projections trying to help him).
They remind him of numbers from the previous dream (which he thinks is a reality) and he leads them to a hotel room with those numbers.
Then his projections of Browning show up and we see that Robert is turning against Browning when the dream Browning admits to working with his captors.
Then it's time for Level #3.
They convince Robert they are going into Browning's subconscious to find out what he's hiding when really, they're going into Robert's.