Building views relationship with location I have an article and food content types. I use location module fields in both content types. So for example, when I write an article about restaurants in New York, I choose article's location as country: US, state: NY and city:New York. Now, I want to be able to show related food items in view with same country, state and city. Now, how do I display food items matching with article's location.
Sibling items are usually displayed with the help of two Relationships and one Contextual filter. 

Create Food item Views. 

You first add the Relationship for your Location field, it introduces info about the Location. 

Then you add the reverse Relationship to the first one, it will use the first Relationship. The second one points back to the content that is using that Location field. 

Add the Contextual filter for Node ID and make it use the second Relationship. Set it the usual way, default value and ID from URL, validate against Article Content type. 

I haven't tried this with the Location field but the logic should be the same.