Both Uses

liaison
in
The Hunt for Red October
(Auto-generated)

Those connections had made him valuable enough that the CIA asked him to be part of a joint American-British liaison group.†
Chpt 4. *
His value as a liaison officer was unsurpassed.†
Chpt 12.

Definitions:

(1) (liaison as in: She is their liaison)
a person with the role of increasing communication and cooperation between two organizations
(2) (meaning too rare to warrant focus)
In classic literature, liaison can refer to a sexual meeting or affair -- especially one kept secret. Liaison can also reference a communication link or an instance of communicating. Even more rarely, liaison can reference something used to thicken a sauce while cooking.