How to create a Views relationship using the Address Field module?
The country should be filtered by the current node's title


The better approach is to create Taxonomy Terms, so you can tag your nodes.  

In admin/structure/taxonomy Add a vocabulary called Countries. 

Then add a term reference field to your content type and select countries as your vocabulary, and use auto complete widget.

So all you have to is type the country name here and it will tag your node with that name. 

In views, for contextual filter add Has taxonomy term ID



PS: You could use the Rules module to auto tag your nodes based on the Country field value.