Different apps on the same account

Sorry if there is already a similar question but my search did not find an answer to solve my doubts.

I have different applications in the same account, where we have created different events( event hooks) and different custom fields, the point is that we want to execute the different events individually, assign them to a specific application, as well as the custom fields for user porfile of a specific application.

basically I would like to know how to work in the same account with different environments (Production, Staging ,qa) and assign each variable, each event hooks or each api call to a specific application.

Thanks in advance.