The applicants must hold an advanced degree and their employer must be located within the United States. Additionally, applicants must have five years of post-bachelor's work experience. While there isn't a specific definition in law however, the Administrative Appeals Office has outlined various factors to be considered when using the test of national interests to foreigners. The first requirement is that the person applying have unique knowledge and abilities that are beneficial to the nation. They must work in an area where their expertise will help the nation.

https://en.wikipedia.org/wiki/National_Interest_Waiver