AdvancedDataGrid - Grouping for aggregations embedded in flat data

Question

Hi.

I have some data like so :

{
     { total : 300, year : 2001 }, // total for the entire year
     { total : 300, year : 2001, quarter : 1 }, // total for an entire quarter
     { total : 250, year : 2001, quarter : 1, month : 1 }, // total for a specific month
     { total : 275, year : 2001, quarter : 1, month : 2 },
     { total : 300, year : 2001, quarter : 1, month : 3 },
     { total : 300, year : 2001, quarter : 2 },
     { total : 250, year : 2001, quarter : 2, month : 4 },
     { total : 275, year : 2001, quarter : 2, month : 5 },
     { total : 300, year : 2001, quarter : 2, month : 6 },
     { total : 300, year : 2001, quarter : 3 },
     { total : 250, year : 2001, quarter : 3, month : 7 },
     { total : 275, year : 2001, quarter : 3, month : 8 },
     { total : 300, year : 2001, quarter : 3, month : 9 },
     { total : 300, year : 2001, quarter : 4 },
     { total : 250, year : 2001, quarter : 4, month : 10 },
     { total : 275, year : 2001, quarter : 4, month : 11 },
     { total : 300, year : 2001, quarter : 4, month : 12 },
}

As you can see, the aggregations are embedded in the data. Objects missing the quarter and month fields are aggregations for the year, and those missing the month fields are aggregations for quarter.

The aggregations don't follow the inbuilt aggregations of MAX, MIN AVG etc (it is a last-non-empty column, FYI). Is there a way to group this data in an AdvancedDataGrid?

Thanks.