@Hari_Dutt - I enabled tracing, and see that the method Erp.PriceLstHed.GetList is called when searching for a Price list in Price List Maintenance. So you might need to put the BPM on that BO instead of Erp.PriceLst.GetList -
You might need it on both (or maybe even more), as I see multiple potential BO’s
And some of them have multiple Methods that might need the BPM. For example, BO PriceLst has methods:
GetList and GetListFilterPriceList
Use tracing to find out which which BO and method you need.