VoiceOver will traverse elements from left-right, and from top-bottom. If for any reason you need to change that order, in SwiftUI you can change the accessibility sort priority. A higher priority number in the container means it will go first.

There are five buttons labeled with A, B, C, D, E. The A button is first, B is underneath it, and C, D, and E are under B. The natural order with VoiceOver would be A, B, C, D, E. There is some code that gives C a sort priority of 2, D a sort priority of 3, and E a sort priority of 1. That means that the order will be A, B, D, C, E instead.