Hi @v-mingkz-msft
Thanks for that solution, that is exactly what i am trying to do.
As said, i am very new to power apps and don't have experience. This is my first project.
I have tried to implement your solution, but I always get error messages.
Do i need a gallery to get this running?
I made a gallery, and put in your code with my List-Seetings as following:
AddColumns(GroupBy('Magazin-Sales',"Artikel","NewGroup"),"ChartItems",Table({Value:100-Sum(NewGroup,Anzahl),label:"Gap"&"-"&100-Sum(NewGroup,Anzahl)&"%"},{Value:Sum(NewGroup,Anzahl),label:"Achieve"&"-"&Sum(NewGroup,Anzahl)&"%"}))
This is my SP-List:

I get always an error here:

Function GroupBy has invalid Arguments.
"Artikel" -> Text, Number, boolean or date/time expected (something like this, translated from german)
I can't find out the problem with this function?
Best regards
Stephan