Hi , I've come up with a way to do this using data model techniques. In this example (similar but not same as yours) i have a drill from Year to Month (MMM) to Date
Need to create a table for each level in the drill down and use ORDER BY DESC to filter the negative values of Year,Month,Date to get the ascending order you want in the chart.
In the sample below, my drill down dimension is made up of OrderYear,OrderMonth,OrderDate. The 'fact' keys are just for joining and sorting . In your case you could add a weeks table. Hope this helps. Let me know if you can't get it to work.
OrderDate*-1 as OrderDateFact,
Year(OrderDate)*-1 as OrderYearFact,
Month(OrderDate)*-1 as OrderMonthFact,
FROM [lib://Individual XLS/OrdersHeader.xlsx]
(ooxml, embedded labels, table is OrdersHeader);
fabs(OrderYearFact) as OrderYear
order by OrderYearFact desc;
left(monthName(date(fabs(OrderDateFact),3)),3) as OrderMonth
order by OrderMonthFact desc;
date(fabs(OrderDateFact)) as OrderDate
order by OrderDateFact desc;