Note: Doc team updates the current version of the documentation and the
two previous versions (n-2), but we address *only high-priority, or
customer-reported issues* for -2 releases in support.
Describe the changes in the doc and link to your dev story:

1. - [X] Mandatory: Add the required version to the Fix version/s field.

2. - [X] Mandatory: Choose the type of documentation change or review.

• [X] We need to update to an existing topic

• [ ] We need to add a new document to an existing section

• [ ] We need a whole new section; this is a function not
  documented before and doesn't belong in any current section

• [ ] We need an Operator Advisory review and approval

• [ ] We need a z-Stream (Errata) Advisory and Release note for
  MCE and/or ACM

3. - [X] Mandatory: Find the link to where the documentation update
should go and add it to the recommended changes. You can either use the
published doc or the staged repo for this step:

Note: As the feature and doc is understood, this recommendation may
change. If this is new documentation, link to the section where you think
it should be placed.

Customer Portal published version

https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.12

Doc staged repo within the ACM Workspace:
https://github.com/stolostron/rhacm-docs

The only current doc I found for ClusterPermission is here however ClusterPermission is not only for Gitops, it offers a general way of giving permission on managed clusters.
https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.11/html/gitops/gitops-overview#creating_a_cluster_permission

Creating a ClusterPermission using existing roles

In the previous section, new roles will be created with the ClusterPermission resource. However, the ClusterPermission resource can also be used with existing roles if new roles are not needed. In this example, we are going to create a ClusterPermission using existing roles or cluster role.

Example YAML:

apiVersion: rbac.open-cluster-management.io/v1alpha1
kind: ClusterPermission
metadata:
  name: clusterpermission-existing-role-sample
spec:
  roleBindings:
    - name: default-rb-cluster1
      namespace: default
      roleRef:
        apiGroup: rbac.authorization.k8s.io
        kind: ClusterRole
        name: argocd-application-controller-1
      subject:
        namespace: openshift-gitops
        kind: ServiceAccount
        name: sa-sample-existing
    - name: kubevirt-rb-cluster1
      namespace: kubevirt
      roleRef:
        apiGroup: rbac.authorization.k8s.io
        kind: Role
        name: argocd-application-controller-2
      subject:
        apiGroup: rbac.authorization.k8s.io
        kind: User
        name: user1
  clusterRoleBinding:
      name: crb-cluster1-argo-app-con-3
      roleRef:
        apiGroup: rbac.authorization.k8s.io
        kind: ClusterRole
        name: argocd-application-controller-3
      subject:
        apiGroup: rbac.authorization.k8s.io
        kind: Group
        name: group1 

In the above example, we are no longer specifying a `spec.role` or `spec.clusterRole` field. The `roleRef` field under `spec.roleBindings[n]` and `spec.clusterRoleRinding` refers to existing roles and cluster role on the managed cluster. Also an optional `name` field can be used under `spec.roleBindings[n]` and `spec.clusterRoleRinding` to create the RoleBinding resource using a custom name instead of the default ClusterPermission name.

4. - [ ] Mandatory for GA content:

• [ ] Add steps, the diff, known issue, and/or other important
  conceptual information in the following space:

• [ ] *Add Required access level *(example, *Cluster
  Administrator*) for the user to complete the task:

• [ ] Add verification at the end of the task, how does the user
  verify success (a command to run or a result to see?)

• [X] Add link to dev story here: https://issues.redhat.com/browse/ACM-18987

5. - [ ] Mandatory for bugs: What is the diff? Clearly define what the
problem is, what the change is, and link to the current documentation. Only
use this for a documentation bug.