Associations with nested data

How would I define an attribute within nested data? I tried this but the consignmentBuyer.location object is not converted into a Location model.

attributes: {
        location: 'App.Models.Location.model',
        'consignmentBuyer.location': 'App.Models.Location.model'
    },

I should note that defining it like this didn't work either.

attributes: {
        location: 'App.Models.Location.model',
        consignmentBuyer: { location: 'App.Models.Location.model' }
    },