Reza Rad looks at using Power BI groups and integrating with Office 365:
When you share a content with an individual in the organization, if that person leave the company, or be replaced by someone else from another team, then you have to remove sharing from previous user account, and assign it to the new user account. Best practice is to share content with groups. and members of Groups then easily can be managed by an administrator. Power BI groups are fully synchronized with Office 365 groups. once you used a group in Power BI, then it is only an admin’s task to add/remove members from it.
I like this group-based approach a lot, as it makes dashboard security a lot easier.