A cross-departmental environment is one where teams from different groups, or business units, work together to achieve a common goal. This situation could mean that Admin Assistants collaborate closely with the accounting department, or marketing and sales work together with admin to reach a particular goal. Cross-departmental collaboration can often involve working with people who have varying seniority, which will offer you a broader range of exposure to a business setting. Show the interviewer that you are excited about these opportunities to collaborate cross-departmentally. If you have exposure to this type of working environment, be sure to outline this for the interviewer.