While creating or editing a device, within the device interface, you can select one or more locations from which the device will send monitoring requests. For more details, see the Monitoring agents article.
Clicking on a continental region will select or deselect all locations within that group. To view all locations of the region, expand the corresponding group by clicking the content disclosure arrow next to the group name.
If you have created private agents, you can select them in the Private Agents group.