Auth0 Actions - Using ManagementAPI with multiple applications in the same tenant

We would like to have the user’s database separated as a user that is allowed to login in the Test environment is not necessarily allowed to login in the Dev environment. Could I have achieved this with a single client/application?

We do use the clientID and clientSecret on our .Net api but not for the login calls.
For the login API calls, we are sending the username/password to validate the credentials and using Actions to manipulate the jwt.

Does this clarify? Not sure if that is what you meant when you said “external apps”.

Thanks