Use the following steps to create labels and add devices:
From the Devices tab, enter a new label name in the Labels field.
Select Add (or press Enter) to create the label and add it to the list below All Devices.
Select the devices to add to the label and drag them to the new label. The icon changes as it is being dragged. When the device is directly on top of the label and shows a green + sign, drop it into the label group. Continue to drag and drop devices into the label group until all are present. You can also drag multiple devices at one time by selecting all devices first, then dragging the group to the label.