Power BI Report Builder: propagate value of parent column group

Question

I have a problem in Power BI Report Builder. As dataset I have a table similar to this:

ID	Parent Group	Child Group	Count
1	A	A1	1
2	A		1
3	A	A2	1

And i have to generate a Report Builder tablix like this:

ID	A
	A1	A2
--	--	--
1	X
2	X	X
3		X

So I have to populate rows with the rules:

• if the orginal row is related to a valued Child group (i.e. ID = 1 and ID = 3), the result row has to be populate with 'X' only for the current Child Group
• if the original row NOT is related to a valued Child Group, but only to a Parent Group (ie ID = 2), the result row has to be populate with 'X' for both Child groups.

I tried with InScope, RowNumber... but i couldn't find a solution. Can you help me?