Reading Data Source with Kettle Transformation File in BI Server 5.0

I realized that BI Server 5.0 use Jackrabbit as repository for all solution files including Kettle's transformation file. I manage to upload it, but cannot execute the transformation file. Then I create an action sequence xml file to execute it, and it works.

Now, how can I read the data source that is defined in Pentaho BI Server 5.0 through it?

Thanks,

Feris