Tablix: blank cells when adding new child column groups - reporting-services

Question

I have a dataset with the following fields:
SampleHour
Value
MeasureType
Line
Header
AggregationON
I've created a tablix with a row group on SampleHour and I'd like to have two adjacent column groups, each having the same grouping hierarchy as follows (from parent to child):
AggregationON > Line > Header > MeasureType
Well when I define the first column grouping structure all works fine: I add a parent column group on AggregationON, then a child group on Line pointing to the AggregationON group and so on.
Then I try to create the second column grouping structure and I proceed like this: I point to AggregationON in the first column group and choose "Add Group->Adjacent Right" and specify AggregationON as the "Group By" parameter. The newly created column group header AggregationON appears just on the same row as the previous AggregationON header as expected.
Then I point to the newly created AggregationON and choose "Add Group->Child Group" and set Line in the "Group By" parameter: this time the Line group header cause tablix to add a new row. On the left of the newly created header appears a blank new row that is impossible to delete.
If I go on creating child groups to build the whole column group structure, each new column child group will add a blank row on the left. That leads to an unacceptable table header with a mix of texts and blank cells like in the attached screenshot. Any suggestion?
(Creating two column groups with the same structure is due to the need to filter out results differently in the two groupings)

Answer 1

When you create the second column group use the "Column Groups" section on the bottom pane. Click the arrow on the first parent group and select Add Group -> Adjacent After.
Then add the child groups normally and you'll end up with something like this:
Now all you have to do is move the Child1 and Child2 to the rows below, and delete the 2 new rows choosing the option Delete rows only and you will have the two groups side by side.
Other way to tackle this problem is to have only one group (since in your case the grouping rules are the same) just create a parent group that groups based on the filters you want to apply:
Group on: =IIf(<filter expression>, "Group1", "Group2")
This is potentially harder because if you have different rules for each group, you have to put them on every single textbox under this new parent group. But at least it should get the result you want.

Answer 2

I had a similar issue. What worked for me was to use "Merge Cells"
Group1....................Group2......................Group3
Group1a.....................................................
.........................Group2a............................
.....................................................Group3a
In example above Group1a merges with blank cells below, Group2a merges with blank above and below, and Group3a merges with blank cells above. Then just resize the row.