The Access Request Decision event trigger only fires when all approvers have finished, so there really isn’t a way to be notified of each approval stage.
The Access Request Dynamic Approver is how you can accomplish this use case. This trigger allows you to add a single approver to an access request based on any arbitrary criteria you have. If you need additional approvers, you can always send forms from workflows to any number of additional approvers. The forms will sidestep the built-in approval chain, but it will allow you to have more dynamic approval processes.