A custom_field_dependency makes one custom field (the child) depend on the value of another field of the same field_type (the parent, always single_select or yes_no). It works at two levels. At the field level, parent_custom_field_option_ids / parent_boolean_values list the parent values that show the child: while the parent holds any other value, or is unanswered, the child is hidden. At the option level, option_mappings restrict which of a select child's options are allowed for each parent option. Greenhouse judges dependencies against the record's values after a write, including values set in the same request, and does not keep a value written to a hidden child (or a child option the parent's value disallows). A child is also hidden whenever its parent is hidden, whether by its own parent or by /v3/custom_field_offices / /v3/custom_field_departments scoping. Only dependencies whose child is a job, opening or offer field are listed, since those are the custom fields Harvest writes. Before writing a custom field on a job, opening or offer, filter by child_custom_field_ids to find what controls it, and set the parent in the same request if needed. Returns no rows when the organization does not have custom field dependencies enabled.