link combobox with sap bw data

Hi,

I have a dashboard connected to a bw query. I would like to create a combobox and fill it with my characteristic "country".

So I have linked a range of cell with the key of that characteristics and an other range of cell for the text.

I linked my combobox with that text range but my combobox hasnt any value. In usage tab I also checked "load before run"

What could be the problem ?