You or the business must have the nationality of the treaty country. Your nationality is determined by the laws of your country. The nationality of a business is determined by the nationality of the owners of that business.
Where the business is incorporated is irrelevant to the nationality requirement. The adjudicating officers will look into whether 50 percent of the nationals of the treaty country own the business. If the business is a corporation, the officers will look into the nationality of the stockholders.