Dependent Value Sets.

Hi All,

I have an Independent Value Set named Country. Values within that at UK, US, India, etc.

I then have a Dependent Value Set named City and depending on the value selected in the Independent Value Set, the list of values in the Dependent Value Set is presented.

I now want to introduce a second Dependent Value set, named Town, which is dependent on the City Dependent Value Set.

How do I functionally set this second Dependent Value Set up as when I select the Value Validation - Validation Type as Dependent, I have to assign the Independent value set, meaning wne I come to assihn my values into the Valus Set, the Independent value set is key.