Approver groups are the ordered tiers of approvers inside a single approval flow on a job or offer. Each group has its own approvals_required threshold (e.g., "any 1 of 3" or "all 4") and resolves as approved once that many of its members approve, or as rejected once enough members reject. Groups with a lower sort_order must resolve as approved before later groups become actionable. Filter to a specific flow with approval_flow_ids and look up the individual people in each group via /v3/approvers?approver_group_ids=. To restructure the tiers themselves, use PUT /v3/approval_flows/{id}/replace_approver_groups; to swap one person within a group, use PUT /v3/approver_groups/{id}/replace_approver.