Hi Arpit,
Initially you need to maintain the realignment table - It will based on your MPOS. For example below screen shows that a table defined where data would be copied from Product FG01 to FG02 based on given set of characteristics. After you have defined the setup you can also select the key figure for which you want to copy the data from source to target.
After you have defined the steps - you can execute and then see the result in planning book.
Hope it helps.
Regards,
Alok