Distinguish user permissions by different API's

I have multiple API’s with obviously different permissions and I want to access those permissions in the ID token so that my SPA can implement the correct behaviour for this user’s permission.
Previously I had only 1 API/Audience and I implemented this on Custom Rule solution, but now i have another API with another Application and i want to get the correct audience permissions for this user.

What’s the best approach to make this possible?