as you can see in the help page:
In bar charts with multiple dimensions, sorting is locked to the first dimension. This dimension is what groups and stacks are based on, and sorting on a different dimension or a measure would break up these groups in an undesirable way. If you still want to sort by the measure value, try using the option Sort by expression on the first dimension under Sorting.
It is not possible.
thanks for ur answer. I know this way of sorting but the problem is that the combination of product and size sorted by a measure seems not to be possible.
Here a little example. As u can see it is sortet but not how it used to be with sorted by measure.
And when i turn it around so that the size is dimension number1 i dont like the way it shows the article.
cause then the product name is shown under every bar and thats not nice to look at.