"To have a role" means to have a specific job or responsibility in a certain situation or group. It implies that you are expected to contribute and perform certain tasks or functions. Full definition
The study showed that this brain region likely also has a role in decisions about which directions to face next to get where we want to go. (sciencemag.org)
Further results suggest these waves could also have a role in supporting the brain's representation of space. (sciencedaily.com)
How has the role of women in work changed? (tes.com)