I have a content type called
Packages.Each content has two fields:
Continent(this field was created using the module Countries).
I have created five contents of content type
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.