Hi,
I don't think that option is available. You can export to 2 files and can combine, if that's required.
The stock and % shows if you go for ABC analysis. But, in that case, system classify the stock into 3 segments and the display is limited to ABC categories.
In your case, export will be an easier option. Since material codes are same, just need to combine the 2 columns.
Thanks
Prem