When I configure a binding source to support a particular binding manager, I just set the DataSource property of the binding source to something that will populate it with the entities of interest.
For example, I might have a line of code that reads:
orderSummaryBindingSource.DataSource = mPm.GetEntities<OrderSummary>();
orders = mPm.GetEntities<OrderSummary>();
orderSummaryBindingSource.DataSource = orders;
where mPm is a PersistenceManager instance.
I guess I don't understand why you think you need to create distinct DataSource objects to populate binding sources. If you could explain this to me then perhaps I would better understand your difficulty.