Best practices for writing App Spec file with multiple environments

Hello, I’m working on writing a YAML App Spec file for a Node api application. I haven’t come across any examples that show how to handle the scenario of deploying multiple environments, such as a test, staging, and production environment. Is there a common best practice way of doing this? Should I just have three entries under “services” in the spec file that use the same repo or image but use different branches or tags? If I did, is it common to “namespace” the service names with the environment, such as “my-app-prod-”, “my-app-staging”, etc?