How to load nodes that are associated with the child of a taxonomy term
visabhishek answer gave me an idea.

Create a tax term page view: 




Add Legacy ID as your contextual filter
In FIELDS add term ID (so you will get the term ID of Area 1. You can hide it using exclude from display.)


Then using the Views Field View module


  This module allows you to embed a view as a field in a view. 



Add the view from visabhishek answer as a field. For Contextual filter you can pass the term ID as a token (using replacement patterns)


Problem solved :)