play a role in (something)
1. To have a specific involvement or participation in something. There's no use lying to the committee, Mr. Marshall, as we know for a fact that you played a role in hiding your company's losses from its investors.
2. Literally, to have a job portraying a certain character in a performance. I hear that Samantha is playing a role in some new film. She's really making her way into the big leagues!