Hi Niranjan,
My suggestion is to use another DataSource, i.e. 2LIS_13_VDITM (Billing Document Item data). Here you have the NETWR field available w/o any enhancement. You can then do a lookup in a BW Transformation.
The field NETWR is a calculated field and present in both VBRK and VBRP. It depends on your requirement, do you need the header conditions or item conditions?
The field NETWR is always in Document Currency (i.e. WAERK).
Best regards,
Sander