Compartment - Tag all the child compartments
Set the OCI_COMPARTMENTS environment variable with the parent compartment OCID like below.
export OCI_COMPARTMENTS=ocid1.test.oc1..<unique_ID>EXAMPLE1-compartmentId-Value
The following example policy will tag all the child compartments under the specified parent compartment with a specified freeform tag
policies:
  - name: filter-and-add-tag-on-child-compartment
    description: Filter and add tag on the child compartments
    resource: oci.compartment
    actions:
      - type: update
        freeform_tags:
           "custodian_development": 'true'