Once the uni_group is created and a membership_rel added of subtype parent_rel, I added this group via a composition_rel of subtype club_cyclist_rel to a group of type unicycle_club.
I then created a relational segment on the unicycle club group for rel_types of parent_rel. As I expected, the parent of the uni_group is now part of the relational segment for the unicycle club.
=# select * from party_approved_member_map where member_id = 823;
party_id | member_id | tag
----------+-----------+------
1185 | 823 | 1174
1177 | 823 | 1174
1169 | 823 | 1174
1161 | 823 | 1174
-1 | 823 | 824
291 | 823 | 824
-2 | 823 | 824
823 | 823 | 0
The composition relationship has created the top two rows, 1177 due to the membership_rel now applying to the unicycle_club group, and 1185 due to the parent_rel now applying to the relational segment on the club group. So, adding one composition rel has resulted in the unicyclist being a member of the club, and their parent being a member of the parents rel segment for the club.
