Pattern/Design approach to retrieve a specific object from various unknown sources

I'm looking for a efficient way of retrieving an object for a specific class from a variable number of classes with a common parent.

in simple terms looking for Object of ClassA

Class B C and D all have method of different names to get said object. Sometimes I may need to access other objects within them to find my desired object.

I was just making a singleton class called

ObjectRetriever with one method called getObjectFromSource(Object source)

The method is currently just a series of if source instanceof ClassC to do specific behaviour.

I'm limited to how much source I can share but was hoping there is an existing pattern/design approach for this.