How can we populate child relation of a parent relation in api response.

[atul1104]

How can we populate child relation of a parent relation in api response. i was able to fetch only parent relation field and not child relation present within parent relation.

API: api/menus?nested&populate[items][populate][3]=relation_to_service

In above api "relation_to_service "(parent relation) also has one child relation that is "service-categories".
How do i fetch "service-categories" in API using filters.