You pivot table has a list of cities, but no Territory field:
There is an easy way to create a virtual Territory field:
1) Select the cities in the first territory (Click on first city, Ctrl+Click on others)
2) In the Pivot Table Tools ribbon, click Group Selection.
3) By default, they call the territory “Group1”, but you can click in the cell and type a meaningful name, like “South Florida”. Also, click on the heading cell and type a new name such as Territory.
4) To create the next territory, select those cities and repeat steps 2 & 3.
When you are done, select the Territory heading, click Field Settings, and change the Subototals from None to Automatic.