The job would involve taking care of the whole collection of those goods. Some of the things a typical manager in this position would do include buying the commodity from single or multiple geographical markets, planning its logistics (multi-modal transport and storage), taking care of the customs procedures and paperwork of the different countries involved in buying and transporting the commodity, finding the right buyer for the commodity, managing the payment means, and working on hedging the risk caused by buying and transporting the commodity.
In short, the job would involve Operations/Supply Chain, International Trade, and a little bit of International Finance.