And I want the XXXXXX to be the maximal rank of my measures. It is supposed to be, for a given selection with my filter panes, a constant value. However, I have tried few things and I've observed that having a constant expression in a chart dimension seems to be impossible. For example, I can't choose max(aggr(Measure,Dimension)) as a chart dimension. So is it possible to compute XXXXXX to be the maximal rank of my measure (so the rank of the lowest value of my measure) such as it is a constant value for a given selection ?