First select a Device in the Devices pane by clicking anywhere within the row.

The device name will become bold as shown...

and then click the Quick History Slider icon at the top of the Devices pane as shown:

Next, move the sliders left and right to set the start and end time and date for which you wish to view device movement as shown:

Then click "Show" to see the route and route markings on the map... easy!

Tip! You can zoom in and out using the plus (+) and minus (-) icons on the map or use two fingers and pinch to zoom in and spread to zoom out!