After logging into Director, choose the Pricebook module.
Within Item Details, navigate to the applicable item.Choose the Manage Discounts link.
This will open the Discounts’s Item Is In window.
From the discount dropdown
choose the applicable discount name
choose “Add To Discount”
Items can also be removed from discounts from this same window. Items can also be removed from discounts from this same window. Choose the Remove From Discount option when in the Discounts’s Item Is In window then Close. Choose Save to apply changes to items.