The general answer I have is that business logic normally fits into two categories:
Object Oriented Business Logic: Gets modeled as objects (in the model), usually injected as repositories.
Procedural Business Logic: Goes in a service with an interface that can be injected into a controller.
Controller Logic: Logic that controls how commands are received and passed to the models/services, then how those results are passed to the view.
Controllers should have no business logic, it's a very specific part of a design pattern for controlling how a user interface passes input off to the models that handle business logic (or services if your problems are more procedural in nature).
