Hi Jaydeep,
If you go to any report and take the datasource id.
Now in the Business Analytics workcenter view Navigate to Design & Assign Reports view and search for the data source.
Basically it will display all the reports in which this particular data source is used.
Addtionally search for help documents like..'Overview of data sources in SAP Business ByDesign' in which you can see for each datasources its Characteristics & Key figures that are associated with the data sources.
Thanks
Lokesh Sharma