Source Tables and Fields

Hi Experts,

Is there any documentation or any TCode or Program or FM to find from which table and from which field the data sources (2LIS_11_VAHDR, ..........) are extracting the data. I mean in DSs we have n no. of fields, from which table and from which field these fields(in DS) are getting data when i check in RSA3.

Plz can any one help me in this regard...

Thanks & Regards

Ramakrishna Kamurthy