While I was working for Company X, I gave my father a letter to support his B-2 visa application. I now moved to Company Y. Does he need to apply for a new visa?

Answer

No, your move to a different employer would not normally have any impact on your parent’s B-2 visa. Even if he submitted a letter of support from you when he applied, his B-2 visa would not typically be tied to you or your immigration status in the U.S. (04.Sep.2019).