This plugin allows you to configure discounts for customers who have purchased at least one of the specified products (in previous orders).
Discount requirement rule is a logical dependency in nopCommerce discount module that defines whether a discount applies or not, according to its conditions.
nopCommerce site: https://www.nopcommerce.com
Listing on nopCommerce "extensions and themes" catalog: https://www.nopcommerce.com/had-purchased-one-of-these-product-discount-rule