Second paragraph of the documentation here:
https://stephensherrardplugins.com/docs/woocommerce-user-role-minimums/
If you use both Order Quantity and Order Amount minimums, you can choose if the operator for those values is “AND” or “OR”. “AND” means both order minimum conditions must be met to check out, while “OR” means they only need to meet one condition. Version 2.1 also adds optional maximum values for the order amount and order quantity minimums sets. If a maximum value is set (amount or quantity), that is treated as a hard limit and the customer can not checkout if they exceed the maximum value for order amount or order quantity.