There is no direct answer for this question as per scrum methodology.
It depends on how many products your organization building.
Most of the first time readers on Agile Scrum website can think/imagine building a small and simple product with a team of 9 and a product owner who reports to stakeholders/CEO
In reality its completely different
I work in largest U.S bank with thousands of projects running inside, imagine how many product owners we have here? whom they are reporting? do they all report to CEO then he will die, if they all report to one stake holder its impossible.
When we have more than 1000 products(leads product owners) - what happens who can make sure all these POs are in right direction?
That is the reason enterprises choose this model
Managing Directors -> then Directors -> Then Senior Vice Presidents -> Then Vice Presidents ->
Then Asst Vice President or product owners - exactly will do what Agile methodology describes about product owners will have full control on their product, above management won't question him on his own decisions about product
Imagine a situation, if this crazy product owner left organization in between before product delivered, how to handle?(large banks have thousand of projects and many PO's and any one can resign any time or something unexpected happen any day)
How to recruit new product owner , Is the newly recruited product owner will have all caliber to deliver what ever road map created by previous Product Owner? it will take some time at least 2-3 months for new person to be fully operational.
Ideally in real Enterprise level its not easy to answer to various stake holders that our great product owner left that is why my project is delayed.
This is where most of the organizations started new role "Product Managers" or "Chief Product Owner" even this is not part of scrum.
So for most of the enterprises, scrum starts only after VP level.
Product Manager will be taking decisions and acting as key stake holder for a larger product which is split and will be dealing multiple product owners in large products - mostly we can find such products in banks ( I am not sure about other organizations)