how can I configure Datasource and Datapoints for Datapoint Aggregator

I want to add a DataPoint Aggreator on the Monitoring Template for Device "/Storage/SMI-S/HP/EVA" (created by the HP EVA Monitor ZenPack). I am not sure what I should fill in for Target fields "Method", "DataSource" and "Datapoint". I have tried values "os.storagevolumes" (corresponds to the component "Logical Disks"), "StatisticalData" and "KBytesTransferred", but this does not seem to work.

Also, I would like the Aggregation to be performed on only a subset of the storage volumes, only the ones containing a specific string in their title. How could I do that