Trying to create an agreement like the European Union for the Commonwealth of Nations

[ferociousblazze]

As the title suggests I would like to create an agreement in the Editor for the Commonwealth of Nations where players would be able to be transfered between member nation before their 18th birthday and not be considered as foreign players. 

Although I can create the agreement and add the nations in the editor I can't find where I can add such conditions. Is it even possible to do something like that? and if yes where should I be looking at?