staff; staff officer
Refers to a group of officers who assist a commander in planning and operations, or an individual member of such a group. Primarily used in military contexts, but can appear in organizational settings.
He planned operations as a staff officer of the division.
The next strategy was decided at the staff meeting.
The general appointed a capable subordinate as a staff officer.
He was involved in drafting the operation plan in his capacity as a staff officer.
She served as a staff officer at headquarters for many years.