C# - How To Access Classes In Sub Referenced Library

I have the following projects:
TradingProject (my code) Has reference to TradingLibrary, and to ApiLibrary?
TradingLibrary (my code) Has reference to ApiLibrary
ApiLibrary (3rd party code)

I'm making several projects (like TradingProject) that communicate with a software through use of an existing ApiLibrary. But I want to push generic methods into a library I write: TradingLibrary.

Still, I would like to use some parts of the ApiLibrary directly from TradingProject. However, I then would need to pass an object (of an ApiLibrary class) into a method in TradingLibrary. Where the object should be recognized. However I assume this will be a problem, as TradingLibrary use it's own reference to ApiLibrary, so it will not be recognized as the same classes? Is there some way I can "forward" the ApiLibrary reference from TradingLibrary to MyProject, such that they will use the same reference? Or do I need to duplicate the classes and inherit from ApiLibrary for each class? Like:

NameSpace TradingLibrary
Public Class SomeClass
Inherits ApiLibrary.SomeClass
End Class

I guess that would work, if I do it for all classes I need, but is there perhaps some simpler way I'm not aware of?