how to link country and location in insight

[Madhusudhan]

We have Insight Schemes where Country and Locations have been stored as objects like in below structure

Object Schema

• Country (10)
• Location (20)

Number in braces indicates  number of objects.

Now, my requirement is these two objecttypes will be used across other schemas as reference. So if I select Country called "ABC" only the related cities should be shown. How do I do that?