Referencing Existing Nodes feature needed.

Or is it exist I just don't know how to do it?

In my opinion the best is an integration with other modules like:
Node Reference Views Select
Nodereference Explorer
or similar

What I see is: you might have different needs for referencing and adding a new node.
Probably a separate module is needed for this:
Multiple widgets at the same time or integration of multiple widgets or similar.

Does anyone have any idea?