Hi Sai,
With the help of MDM syndicator, data from MDM can be sent to BW.
Please tell me if PI is involved in landscape? If so, it will be easier for MDM consultant to create a syndication map which will extract data from MDM and send it to BW via PI. If there's no PI in landscape, then you might have to check use ABAP API's to extract data from MDM. I have not heard of BW using ABAP APIs since it executes report. I have heard of R3 system using ABAP APIs to extract data from MDM.
Flow should be as follows if PI is available in landscape: MDM-->PI-->BW.
Please let me know if any issues/queries.
Regards,
Ali