View of related nodes by continent or country without taxonomy terms I have a content type called Packages.Each content has two fields:
Title and Continent(this field was created using the module Countries).

I have created five contents of content type Package: 
Title        Continent

 London      Europe

 Madrid      Europe

 Paris       Europe

 Brussels    Europe

 Tokyo       Asia

I want to make a block of related nodes by the continent.

For example: if I am viewing the node of London in the block of related nodes show the cities on the same continent in this case: Paris, Madrid and Brussels.

I want to do this without terms of taxonomy, otherwise I'll have to create a vocabulary with more than one hundred fifty terms.
There are like mostly in Drupal several possible solutions. One would be to filter Views views for each view and therefore you can filter any field you want the same way, like you do with terms (check the terms view pages as an example, how to build such filtered views).

Another option would be to create node relations like provided with the Relation module or the Entity reference module. The advantage of the relation module is, that the relations are own custom entities which are fieldable again, like term view pages. Thanks to @diqidoq for pointing me to this solution.