Your solution is perfect, but I have little problem.
I tried to modify in different ways your formula before ask you but I couldn't achieve a result.
I want order the rows based in other table with the same rows but ordered by other column.
When I modify the ALLSELECTED like below the results is always 100%
% level 3 = DIVIDE(sum('Sales Data'[Sales]),CALCULATE(sum('Sales Data'[Sales]),ALLSELECTED('Item Data'[Item]) ) )
Thanks for your help!