Step-1: General tab
Give the basic details for your discount rule and choose "Quantity Based" as your discount method.
Step-2: Condition tab
In the condition tab, choose
Apply To = Specific products and then select the product for which the discount should be applicable.
For example, select Laptop.
Step-3: Discount tab
Set the discount range and value like below:
Min-Quantity = 1
Max quantity = 999
Adjustment type = Product discount
Value = Select any two products (that needs to be discounted)
Step-4: Frontend demo