Complex sentence: The largest urban area in the United States is that of New York City, with its city proper population exceeding 8 million and its metropolitan statistical area population over 19 million and combined statistical area population over 22 million.
Split into simpler sentences: The largest urban area in the United States is the New York City metropolitan area. The population of the core city exceeds 8 million people, its metropolitan statistical area has a population that is over 19 million, and its combined statistical area population is over 22 million.