The following ACI can be used to allow an employee's manager to edit the value of the employee's telephoneNumber attribute. This ACI uses the userattr keyword with a bind type of USERDN, which indicates that the target entry’s manager attribute must have a value equal to the DN of the authenticated user:

aci: (targetattr="telephoneNumber")
(version 3.0; acl "A manager can update telephone numbers of her direct reports";
allow (read,search,compare,write) userattr="manager#USERDN";)