groupBy

You can group Amazon Web Services costs using up to two different groups, either dimensions, tag keys, cost categories, or any two group by types.

Valid values for the DIMENSION type are AZ, INSTANCE_TYPE, LEGAL_ENTITY_NAME, INVOICING_ENTITY, LINKED_ACCOUNT, OPERATION, PLATFORM, PURCHASE_TYPE, SERVICE, TENANCY, RECORD_TYPE, and USAGE_TYPE.

When you group by the TAG type and include a valid tag key, you get all tag values, including empty strings.