A staff member who keeps up with new regulations, monitors existing ones, and is the "go-to" person should an incident occur is known as the

The correct answer should be something like a department director or anything along those lines. Directors are persons in charge of departments the way that you described it and usually have to answer to someone higher up who's a director/manager for the entire company. If it's a huge corporation those higher ups would answer to a CEO often in a different country, while smaller companies usually have department directors answer directly to CEOs.