Hi srinika,
In specific to a single material's Bom changes you can get through CS14
Here we have primary bom and secoundary bom fill the same material and enter the dates the date on which the changes have come and a past date .
select Differentiated comparison you will be able to find the changes done against each .
Note : This procedure would be helpful only if you are looking for a very few materials Bom's changes
Hope this would help you .
Regards
Arvind