How to define a relationship with two dimensional array of objects in Ember Data

Am new to Ember and still trying to learn its ways. I have two data models say 'foo' and 'bar' in my application. If a foo object has an attribute which is a two dimensional array of items of type 'bar', how do I define the relationship in foo? I am aware of using a hasMany relationship if it is a single dimensional array but am stumped on how to do handle the current scenario in the right way. Appreciate any help! am using Ember 3.8 btw