By default, the manager dashboard only shows data for people that report directly to you, the logged in user. If you'd like to see data for your indirect reports, further down the reporting line, you can do so using the Levels Down filter:
Click the filter icon
at the top of the dashboard.
Expand the Levels Down section.
Select one or more values.
Click Apply.
The dashboard now shows data for all levels that you've selected.
The Levels Down filter shows a value of 1 by default meaning you can see people one level below you in the reporting line – your direct reports. Selecting two shows you data for people two levels below you in the reporting line – the direct reports of your direct reports and so on.