Since you are still developing your database, I would recommend you to divert from your plan to create one list per department. In stead, create one list of all your relevant employee information and include a column that holds the department. You can then easily create summaries (e.g. headcount, FTE, by business unit, by department, by gender), similar to what you describe as what you have in your main menu. The best way would be to familiarise yourself with Pivot Tables and or Filters.