How to bind a reference field to a symbol

What is the solution for it?

I bound this hero reference to my component, but try to bind the property for it:

Like this:

But I got undefined as you can see.
(If I bind model instead of reference, this state.binding works, but not with reference, how can I bind my Hero reference properties like title, subtitle for it, so I can choose my entry on the fly, when I add my symbol to the page)