Chuck convinces Jimmy to bring his case to HHM because of its large scale, which may lead to it becoming a class action suit.
Chuck and Jimmy meet with Hamlin, who is eager to take on the case. However, Hamlin insists that Jimmy not work on the case.
It looks like his own brother never considered Jimmy a ‘serious’ lawyer and sabotages his future employment. This ends with Jimmy leaving Chuck, presumably for good. Everything is coming into alignment for the Saul we see at the beginning of Breaking Bad.