If you have an exposed reference on a clip, you can resolve it at run-time using the ExposedReference.Resolve method. The resolver you likely want to pass can be found by calling the GetResolver method on your playable graph.
However, the snippit you’ve posted is an example of accessing an object that’s been bound to a track using a Track Binding. This is accomplished with the help of a PlayableDirector component and is (a bit confusingly) distinct from the concept of an ExposedReference.
This thread might be helpful for what I think you’re wanting to do: