You can export the catalog you create in your main class and then import it in the other parts of your app that want to utilize it.
You can also create a global static that holds the main catalog.
You can also use Unity or some other IoC Container to inject the container into your other class instances.
In my app, I create a class that has one member that holds the container. I declare an [Export] member instance of that class. I create an instance of this class, create the container, set the property of my class to the new container.
Then I compose myself. All objects created as part of my compose can import the container class.