Mostly interviewer asks this questions to check your career goals. Hiring a new employee is costly, so he or she wants to be sure that you are coming on board for a long time or not. The interviewer will also get to know how realistic you are with your career prospects.
You can answer like this, " I see myself having grown both with regard to expertise in my field as well as with the company. I picture myself in a leadership role, contributing more to the growth of the organization". Also, you can add " I see my growth in my own skills and capabilities". Its a good way to convey your opinion.