How to add multiple discounts in Purchase Order?

I want to add custom field same like Additional Discounts in purchase order , we have two different discounts like Retention Money - 2% and TDS - 1% , I need to calculate and print these two fields separately.

Tried creating new custom fields by copying additional discounts field but it doesn’t calculate the amount when we enter percentage. How to make this to work?

The TDS your customer deducts or you deduct to your suppliers is not a discount. It’s a tax your customer or you collect on behalf of the government. It should be recorded separately in a tax account.

You could tax and charges template for doing it.