supplementary curator
A person appointed by the family court to represent a minor child wherever the parents are legally barred from acting (Section 1809 BGB) — for instance because a parent is a co-heir themselves. For adults under guardianship, a supplementary guardian appointed by the guardianship court takes this role (Section 1817 (5) BGB).
German: Ergänzungspfleger
This explanation is for orientation; German law applies. No legal advice in individual cases.