As you transition from the role of individual contributor (IC) product manager to managing product managers, there will be a change in expectations and definition of success in your role. As an IC PM, your success is mainly defined by your ability to dive deep, show bias for action and perform timely execution. While as manager of PMs, your success will depend on your ability to delegate, think big, and grow and develop your team members. Navigating this transition is an art, which can be perfected with guidance and practice. It is also an iterative process, which must continuously evolve with the company goals, stage of the product and the working styles of the people reporting to you. From my personal experience, here are the key takeaways that summarize how one must evolve as one transition from IC PM to Manager of PMs:  

1. Art of Delegation: As an IC PM, one has to focus on the end to end ownership of the product life cycle, but as Manager of PMs one has to delegate the key product functions effectively across all the team members. I call delegation an art because the manager has to ensure that each team member gets tasks that speak to their strengths, challenge them to push their boundaries, and provide them enough scope for learning and development. Also, delegation has to be proportionately balanced across all team members based on their skill set, work experiences, nature of the product, and focus area.
2. Big Picture Thinking: As an IC PM, it is critical for you to be very close to your product operations on a daily/weekly basis to keep a pulse on feature development, user adoption and engagement metrics, weekly sprints, etc. However, as a Manager of PMs, you have to zoom out and balance the granular product operations with strategic and big picture thinking that clearly defines the product vision and strategy for all team members over the next 2-3 years.
3. Unblocking team members: As a manager of PMs, your success depends on your ability to unblock your PM team members in situations such as conflict in decisions, trade offs or prioritizations, goal alignment and getting timely support from internal stakeholders or teams with dependencies. One of the most effective ways of achieving this is to set scalable processes for product prioritization and decision making in combination with stakeholder management through bi-weekly project reviews and syncs with supporting teams and stakeholders.

In summary, as you transition from the role of IC PM to Manager of PMs, your focus should shift to effective delegation, big picture thinking and unblocking the team members, as and when needed. This is an iterative process and you must be open to learning and continually evolving in this role, based on active listening and learning from regular feedback from all the team members. In this role, you have to let go of a lot of tasks which you previously enjoyed as an IC PM. Letting go lets you delegate effectively amongst your team members, thereby freeing up the calendar to create more time for big thinking and unblocking your team members, when needed.