Intelligence officer

From Memory Alpha, the free Star Trek reference.

An Intelligence officer is a title given to an officer aboard a starship or space station who is responsible for intelligence matters. The officer typically keeps in contact with a central organization for the latest information.

Aboard Deep Space 9, Worf held the position upon accepting assignment there. (DS9: "The Way of the Warrior") Doctor Julian Bashir briefly assumed the post in late 2373, while Worf was serving on the Rotarran. It could only have been Bashir or Jadzia Dax, as only Starfleet officers with a class four security clearance could hold the position. He told Miles O'Brien "All I can do is read these fascinating reports and analyses, and analyses of analyses and then keep it all to myself. Because no one else has a 'need to know'". (DS9: "Soldiers of the Empire")

Worf was also the intelligence officer of the Rotarran. (DS9: "You Are Cordially Invited")

Colonel Kira Nerys' Starfleet alias, Rota, was a deputy intelligence officer. (DS9: "Tacking Into the Wind")

The Romulan Empire typically has intelligence officers aboard their vessels, and Toreth pointed out that they are held responsible for their failures. (TNG: "Face of the Enemy")

Such officers most likely were members of the Tal Shiar.