SSRS Interactive Sort Row Group data by Column Group

In SSRS I am attempting to do an interactive sort on the combination of a column group and a row group.

So my data would look like:

    -------- ------------- --------- -------- -----------------
    Category开发者_JAVA技巧  CampaignType  Campaign  Quarter Value   
    -------- ------------- --------- -------- -----------------
    Cat 1     CampType1     Camp1     Q1      1
    Cat 1     CampType1     Camp1     Q2      4
    Cat 1     CampType1     Camp2     Q1      51 
    Cat 1     CampType2     Camp1     Q1      3 
    Cat 1     CampType2     Camp1     Q2      1  
    Cat 1     CampType2     Camp2     Q1      3 
    Cat 1     CampType2     Camp2     Q3      56 
    Cat 2     CampType1     Camp1     Q1      8 
    Cat 2     CampType1     Camp1     Q3      11 
    Cat 2     CampType1     Camp2     Q1      2
    Cat 2     CampType2     Camp1     Q1      23 
    Cat 2     CampType2     Camp2     Q1      3 
    Cat 2     CampType3     Camp2     Q2      8 
    -------- ------------- --------- -------- -----------------

So I am grouping on the rows by:

-Category

---CampType

------Campaign

Grouping on the column by the row.

Getting the sum of the "Value" at the intersection of these two points.

Add some totals and we're done.

I would like to be able to sort the campaign value sums by quarter.

That, in my opinion seems like a reasonable request.

See below firstly what it looks like in designer and then an example: