displaying nested json in ag-grid

ag-grid field attribute can only refer to a property of the data row, but the valueGetter attribute allows expressions. So, while

field: 'defaultColumns1.region'

won't work, switching to

valueGetter: 'data.defaultColumns1.region'

will work fine. Sample plunker forked from yours is at http://plnkr.co/edit/8enzrjt2MQwfa8VjGaIy?p=preview