Drop Down Menu
To select locations from the drop down you can either type in the location you are looking for (the specific location i.e. San Francisco or the geographic level i.e. county)
You can click on the desired geographies in the drop down menu:
You can clear all selections by clicking the "X" in the righthand corner.
To select locations on a map, click the arrow next to Filter by Locations and select "Map View." You can switch between the different geographic views by clicking on the different geographies on the lefthand side of the map. You can select geographies in that view by clicking them on the map.
You can use the "All" button to select all geographies in that view or use the "None" button to deselect all geographies in that view.