when adding content to panels there is an option "existing node", then new popup is displayed:
Configure new Existing node
Enter the title or NID of a node
After typing node name I could choose a node.
As have many different nodes of different content types with similar names I couldn't easily choose the right node.
It would be useful to see what is a content type of nodes displayed by autocomplete.
I hope this feature could be useful to others also.