Routing Decisions
Consider a process in which a discount is applied to a bulk order as a function of customer loyalty and the number of ordered items. Here’s a way to model the process in BPMN:

It’s precise but cluttered and unwieldy. A business rule task is a better alternative to complex chains of gateways:

The business rule task (“Determine discount”) leverages a DMN decision table, which is flexible and can be modified easily:

So, when you find yourself creating a BPMN process model with nested gateways, you may wish to consider using a business rule task. It’s clearer, more flexible, and just as precise.
