There should be no such position as commodity director. What you want to express is the product manager, PG (product manager), the highest person who manages a single product, such as the small bottled water in Nongfu Spring.

Marketing director is the strategic and tactical angle for the whole company to make marketing plan. For example, the brand Nongfu Spring under Yangshengtang.

The marketing director and the operation director belong to two departments. You can understand them as an OD (Director of Operations) Director of Operations.

Marketing director marketing director

To answer your question, I am looking for books and documents, but it hurts me not to adopt them.