Hi,
Have you tried using Overrides when resolving your instances, this wayUnity allows you to specify constructor parameter or parameters, which could be useful to pass the selected item.
For more information about this you could check the following MSDN article:
Also, I believe you could find the following thread interesting where a related discussion is addressed:
I hope you find this helpful,
Agustin Adami
http://blogs.southworks.net/aadami