How can I make the discounts not to overlap?

To get the desired result place the discounts in order of importance. The higher the discount, the higher its priority.

Let's say you already have a resource with different pricing components. For example, hourly rental with discounts:
1. Birthday discount - 25%;
2. Discount from 3 hours - 20%;
3. Multiple discount - 15%.

And you need to get this:
- If the first discount is applied then the 2 following discounts are not applied.
- If the second discount is applied the third discount is not applied.
- The third discount is applied only if the first two discounts are not applied.

In this resource, the birthday discount is located at the very top. This means that its priority is higher. The discount will work in any case if the "Today is my birthday" checkbox is set. You don't need to change its settings. Go to the next discount.

Open the second discount and click on the Add condition button.

Then pick the option Exclusion by pricing components from the list of conditions. Select the component that should disable this component when applied. In this case it is a birthday discount.

See an example in action.