Management of managers is a very tricky task. It has some elements common to managing any individual contributors but some that are crucially different. Managers need specific management training but instead of focusing on results, seniors need to evaluate how their relationships with team members are working out. A right behaviour model for managers must be etched out and all existing or potential managers must be evaluated against that scale. The best of managers must be complimented in public so that their team members can recognize the importance of their leaders. An apprenticeship model must also be implemented where certain tasks the manager works directly with their seniors. Those seniors must also make the effort to get to know their team members.

Source: https://hbr.org/2016/08/how-to-manage-managers