Behind closed doors, Tulsi Gabbard, the director of national intelligence, met with some of the same F.B.I. agents, members of the bureau’s field office in Atlanta, which is conducting the election inquiry, three people with knowledge of the meeting said. They could not say why Ms. Gabbard, who also appeared on site at the search, was there, but her continued presence has raised eyebrows given that her role overseeing the nation’s intelligence agencies does not include on-site involvement in criminal investigative work.