The scenario is that store owner is going to offer a discount 30% for category A and category B.
For example, the discount should be applied for the products from categories Electronics and Home decor.
Step-1 : General tab
Step-2 : Condition tab
On condition tab, you could choose the multiple categories. Choose the categories (Electronics and Home decor) and click next.
Step-3 : Discount tab
Define the quantity range, choose the discount type and set the discount value and save the rule.
Step-4 : Frontend demo