You can add a filter by clicking on the '+' symbol on the right next to the Filter header in your Member Administration.
When creating a filter, choose the relevant filter type (you can read more about the different filter types and what they are used for here.) The (Dutch) video below shows how to create a filter.
Upon selecting a Filter, its criteria are shown at the top of your screen (as shown on the screenshot below).
Hint: Keep it simple, only choose filter criteria that are strictly necessary!