When I get a list of Tenants in v2, the parent_id is included in the response. The hierarchical project is only available in v3 and the field should not be exposed in v2.
curl -g -i -X GET http://10.0.2.15:35357/v2.0/tenants -H "User-Agent: python-keystoneclient" -H "Accept: application/json" -H "X-Auth-Token: <token>"
RESP BODY: {"tenants_links": [], "tenants": [{"description": null, "enabled": true, "id": "c40e281df0a645fb8e76825b3d133ce4", "parent_id": null, "name": "alt_demo"}, {"description": null, "enabled": true, "id": "d0428b4f33e042d28a688de464c61877", "parent_id": null, "name": "demo"}, {"description": null, "enabled": true, "id": "e1fba1cce31744358506cf414983643a", "parent_id": null, "name": "invisible_to_admin"}, {"description": null, "enabled": true, "id": "f53b55995c1a4f5cace7ed595944ace1", "parent_id": null, "name": "admin"}, {"description": null, "enabled": true, "id": "fd16a8def1d34ad0ba7c793bec61fadc", "parent_id": null, "name": "service"}]}
this looks like we should be filtering the parent_id similar to how we filter domain_id.