Roles are not necessarily associated with jobs or job titles; rather, each role should contain the permissions that are required to perform a specific task or set of tasks.
Managing roles by assessing tasks is easier than managing permissions attached to features or functions. Multiple users often perform the same task, and tasks are often shared across different teams. So, roles can include many users.
For the requisite step-by-step guidance, to define roles, in MC, refer to the Tech. Doc. with the URL below.
Specifically, for granting permissions, utilize the guidance below.
Also, see the snippets below, for more guidance.