Member Group - Family Role Filtering

Could you add "no role" or blank as a filter for Family role in addition to Primary/Spouse/Other Adult/Child so that we can pick up the individuals who are not in a family? We would like to create a Member Group that includes all Adult members and excludes U18s. If we specify Family Role (Primary/Spouse/Other Adult) we lose those Individuals with no Role. This request is analogous to https://feedback.courtreserve.com/communities/1/topics/274-member-report-family-role-filtering which made the same request for Member Reports. Thank you.