"served as liaison" is a proper and usable phrase in written English.
You can use it when referring to somebody who has acted as an intermediary between two or more parties. For example, "Christina served as the liaison between the client and the design team throughout the project."
Agalarov served as liaison between Trump and Vladimir Putin, and the two had planned to meet at Trump's invitation the day before the pageant.
A Free French delegate, Marie-Pierre Koenig, served as liaison between SHAEF and the president of the French Committee of National Liberation, Charles de Gaulle.
The former executive, Patricia Prue, was the human resources director at Tyco and served as liaison to the board's compensation committee.
At the time of her retirement in 1991, she was executive editor in charge of merchandising for Bride's where she managed the magazine's relations with leading department stores across the country and served as liaison between editorial and advertising.
Detectives would want to find any shell casings, said Mr. Paolucci, who retired in 2012 as the commanding officer of the unit that served as liaison between the detective bureau and the medical examiner's office.
Stuart Backerman, a former Jackson publicist who served as liaison to the fans, said by phone: "They're not sitting outside of Neverland for three weeks because he's a great singer.
It also encompassed an array of social-service providers and a dozen or so outreach workers, who served as liaisons with the gang members.
Bethune's administrative assistants served as liaisons between the National Division of Negro Affairs and the NYA agencies on the state and local levels.
RA members served as liaisons between residents and the IPM and evaluation teams, answering residents' questions about the program and providing informal feedback to the teams.
They serve as liaison to both external and internal agencies.
She also serves as liaison to the Lewis Center Advisory Council.
