BOSTON (Reuters) - As your career develops you will probably need to branch out in terms of mentors and who can help you reach that next step, says Harvard Business Review. One great mentor can help you, especially early in your career. But as you progress you need a network of mentors who can broaden your perspective and grant access to new opportunities. Build your mentoring network by creating a personal relationship map. Identify the people you need help from to be successful in your current job and everyone who might help you advance your career. Ask yourself which of those individuals you need to know better. Leverage your current mentors to provide introductions and to fill you in on people's backgrounds, interests, and current projects. With that information, you can make meaningful connections by offering relevant expertise or ideas, or finding other ways to assist.