For an essay question like this, you should take care to avoid writing about leadership in a vacuum.
You may begin with your perspective of global leadership and then illustrate that with an example from your professional life. For example, if you think the hallmark of effective leadership is the ability to seize the opportunities in today's global business arena, substantiate this definition of yours by an example from work life when you identified an opportunity in the global world and ventured to capitalize on that. If you think leadership means taking risks, or owning responsibilities, or motivating people (or all of these combined), illustrate your definition by providing examples from your professional life .
Please remember, your experiences should be the ones in which you challenged yourself and adapted yourself to the changes occurred due to increasing globalization. The outcome of your story should be - what you learned from it, how it enhanced your skills, or how it deepened your perspectives.
I hope it helped.
