Please notice that the dimension value expand for rows where the expression returns a value. If your expression returns NULL for the rows you want to hide, this will be possible with the chart properties settings.
In your example you obviously have a expression result for the rows that you expect to not see. It is fairly reasonable to display calculated results.
There is no simple answer to how you can approach resolving the issue in this specific case based on screenshots. It is a matter of picking a suitable solution based on your application and data model.
Please attach a simple QVW file so that you can get more detailed advise.