List groups in a practitioner's relationship graph

Returns all groups that the practitioner belongs to, including core group attributes such as name, NPI, TIN, and active status, plus metadata for each group. Use this when you need groups with their full attribute data as part of the practitioner's relationship graph; to retrieve just group membership without the attribute detail, use GET /practitioners/{practitionerId}/groups instead. {id} is the certifyPractitionerId and the caller must hold the READ_PRACTITIONER permission.