When adding or editing a dashlet in ENA, you can specify the data source from which the dashlet draws its data in the Dashlet Source field. One of the available options is to set the Dashlet Source to Dashlet. This means that the dashlet you are adding will draw its data from another dashlet in the same dashboard. When you select this option, the Source Dashlet field will appear below, in which you can choose the dashlet from which your new dashlet will draw its data.
In cases where the source dashlet is a table containing multiple objects, the any dashlet that draws data from that source dashlet will be blank until you have selected an object in the source dashlet.
An example of this can be seen on the QoS dashboard for a device. When you first navigate to this dashboard, only the Policy Maps dashlet is populated with data. To populate the Class Maps dashlet, you will need to select an object in the Policy Maps dashlet. To populate the remaining dashlets in the dashboard, you will need to then select an object in the Class Maps dashlet.