SSRS repeat column groups underneath values

Surely this must be documented somewhere but I don't seem to get the google keywords right or something. (i'm not a native english speaker but i'll try to make myself clear)

In SSRS when you create a matrix report using column groups SSRS repeats all values for each group, but I would like to repeat the groups for each value

for example what I have is this

Debit                                Credit
Value in currency| value in USD      Value in currency | value in usd

but what i would like is this

Value in currency                    Value in usd
Debit | credit                       Debit | credit

for some reason I can't get it to work and i can't seem to find the right words to get google to give me the solution.

Thanks in advance!