So the lawsuit is about

accusing them of violating his Fourth Amendment right to protection from unreasonable searches and seizures when they tried to obtain Patel's personal records.

This type of search would require judge signing off on a search warrant to subpoena the records. So I would guess before he can get Wray's and Rosenstein's depositions, Patel would have to prove his 4th Amendment rights were actually violated. I think this would involve working his way up before he gets to the big fish.

To get a search warrant an FBI agent has to provide an affidavit to a judge. So I think this affidavit would need to be looked at to see if there were 4th Amendment violations.

The timing of this in suggests the DOJ may have been looking into leaks of classified information

In 2021, it was revealed that a leak investigation subpoenaed a bunch of folks including Congressmen.

All told, the records of at least a dozen people tied to the committee were seized in 2017 and early 2018, including those of Representative Adam B. Schiff of California, then the panel’s top Democrat and now its chairman, according to committee officials and two other people briefed on the inquiry. Representative Eric Swalwell of California said in an interview Thursday night that he had also been notified that his data had been subpoenaed.

The Democrats got all pissed off about this and supposedly the Inspector General is looking into this.