Sales deal and Promotion problem

There is sales promotion given:

u2022 Dollar Amount Discount

When a customer spends over a certain amount, they get a discount.

These promotions are usually offered in two ways

The first way is a single discount. If a customer spends $XX, they get X% their entire order. As long as they meet that minimum dollar purchase, they get the discount.

The second way is a stair-step or sliding scale discount. If a customer spends $XX, they get X discount. If they spend more, $XXX, they get a larger discount, XX% on their entire order

u2022 An example of this is

o If you spend $100, you get a 10% discount

o If you spend $200, you get a 15% discount

o If you spend $300, you a 20% discount

In this can anyone suggest how can it trigger in pricing???