Tiered volume discounts for select categories only

Objective:

To setup a three tiered % discount discount based on the total number of products purchased in a cart that only applied to qualified products.
e.g. qty 10-19 of qualified products receive 10% off
e.g. qty 20-29 of qualified products receive 20% off
e.g. qty 30+ of qualified products receive 30% off

Any products not in the qualified categories should NOT receive the % discount during checkout.

Originally I thought the coupon would work but the way it works is if any qualified product is in the cart, it applies to the entire cart.

Any solutions to make this possible with this cart?

I have the Business edition.

I've been reading the documentation and it says, "Note that the system will only use one coupon per order and one discount per product."

I have ONE coupon and ONE discount but the coupon is failing to work with the discount. Says it's not allowed.

This needs to work for our store.