I believe your synthetic dimension values should be unique, or how is QV supposed to know which value to choose if you query for e.g. 2011 Cost?
I think you could use two synthetic dimensions e.g. in a pivot table, first like
then in an expression you can query both dimension values by stating the exact valuelist phrases again.
But maybe you don't even need the synthetic dimensions, I think you can also limit e.g. Year dimension just by the use of a calculated dimension, and maybe you already have a FigureType field with values 'Sales' and 'Cost'?
Yikes, that's a mess! If you want to leave the chart like this, I would suggest creating a separate island dimension:
LOAD * INLINE [
Then your chart would look something like this:
Dimensions: Exp_island, Year