In an experiment, pet owners are being encouraged to take their pets to work, a move that some scientists say can be good for both the people and the pets.

参考译文：在一个实验中，宠物主人正在被鼓励带着他们的宠物去工作，一些科学家说这个举动对人和宠物都是有好处的。

a move that some scientists say can be good for both the people and the pets。 a move在定语从句中作宾语从句的主语。

相当于“some scientists say that a move can be good for both the people and the pets”=一些科学家说这个举动对人和宠物都是有好处的。