The DOJ controls the FBI. I haven’t seen anything that indicates FBI is so rogue is can operate on its own.
I figured one dodge that the Biden Administration can use is >>> Lawyers from the National Archive contacted the FBI for assistance in getting documents from Trump that lawfully belong to the National Archives. The Archive's lawyers and FBI lawyers go to a connected DC judge, saying we believe that Donald Trump has a few hundred documents that belong to us. This judge signs the warrant for the FBI to go into Mar A Lago.
BTW -- The FBI raiding party was composed of all Washington based FBI. Not any local FBI