Like you see, in jBPM the identity integration is very decoupled, so if you want to integrate you identity component, the only thing that you should do is to query your identity component for your "users" and then in an AssignmentHandler set the ActorId or the PooledActors property.
I hope it helps!
Thank you very much for your reply salatino.
I integrated my Identity component with JBPM.
See this link for more information:
I guess this will be helpful for others