apiVersion: rbac.open-cluster-management.io/v1alpha1
kind: RoleAssignment
metadata: ...
spec: 
  roles: ["view", "edit"]
  subjects: 
    [
      { kind: "User", name: "kike" },
      { kind: "User", name: "matthew" },
      { kind: "Group", name: "subadmin_group" },
      { kind: "ServiceAccount", name: "serviceAccountX", namespace: "ns1" },
    ]
  clusters: 
    [
      { name: "clusterx", namespaces: ["ns1", "ns2"] },
      { name: "clustery", namespaces: ["ns1"] },
      { name: "clusterz", namespaces: ["*"] },
    ]