Greene, 26, showed off her toned bikini body in a tiny pair of yellow bikini bottoms, opting to go topless as she soaked in the sun, reported Us magazine.
Co-stars Vincent Pastore and Graham Phillips were also spotted on set.
The film, about a few friends who decide to take on jobs as lifeguards while they figure out what to do with their lives, will be produced by 'Saturday Night Live' creator Lorne Michaels.
Earlier this month, Greene took advantage of her temporary residence in New York, exploring the city and even attending the US open.