Thank you very much.
This was the way.
I will explain the situation to make it more clear for the QLIKCOMMUNITY.
In order to avoid circular refernces i loaded twice the same dimension (well one was mapping).
Every thing OK when using them in diferent pages.
But when you need to calculate stuff of the second one in the same page, and the shown (selectable) dimension is the first one.??????
I created a calculated dimension on the pivot table of the second dimenssion based on what was selected from the first one.
=if(WildMatch(GetFieldSelections(CONVENIO),'*'& CONVENIO2 &'*'),CONVENIO2,NULL())
And that did it.
But when nothing is selected, nothing apears....
So created 2 iqual charts where on LAYOUT >>show>> condition...
One has a count(getfieldselections(Convenio)) =0 and no calculated dimension.
and the other has a
count(getfieldselections(Convenio)) >=1 and the calculated dimension.
And works perfect.
Thank you so much.