overseas representative; expatriate employee
Refers to an employee sent by a company to work in a foreign branch or office. Often used in business contexts.
He was posted to Singapore as an overseas representative.
The families of expatriate employees often relocate with them.
駐在員 is a more general term for a resident representative or stationed employee, not necessarily overseas. 海外駐在員 specifically adds the overseas context.
Compound of 海外 (overseas) + 駐在 (residing, stationed) + 員 (member, personnel).