Many successful product managers I have spoken to have said they had (and still have) mentors and coaches. They help you voice your career expectations, identify your blind spots, help you understand what skills you need to develop, and support you along the way.
A mentor (let alone a coach) doesn't have to be your manager, and you can have more than one mentor. Some of them may not even be aware that they are mentoring or coaching you (or you may not be aware of it).
The point is, your growth is in your hands, and if you feel like you're not getting enough support and guidance, it might be a good idea to seek help proactively.
BTW, Sheryl Sandberg in her book "Lean In: Women, Work, and the Will to Lead
" claims that going to a person and asking them to be your mentor is a bad idea. It confuses people and just doesn't work. What works is showing the person that you are worthy of investing their time, asking for specific advice, and building a relationship around it. Or find a mentor through specialized communities or programs where they already confirm their desire to participate.