You can sort measures and dimensions in tables and charts in ascending or descending order, or you can set your own custom order for dimensions. You can sort on multiple dimensions within the chart, but you can not sort on dimensions and measures together, and you can only sort on one measure at a time.
When you have multiple dimensions in your chart, you can apply ranking to one dimension and sorting to another.
Watch this video to learn how to apply custom and advanced sorting.
Break Grouping
Use Break Grouping when there are multiple dimensions in your chart. If Break Grouping is enabled, the sort will be applied to the selected data on the outer dimension only; inner dimensions will not remain in their original groupings. If Break Grouping is not enabled, the sort is performed on the outer dimension first and then inner dimensions.

In the figure Break Grouping the chart on the left literally sorts the Gross Margin number, not keeping them in their respective Region groupings. But the chart on the right has turned off Break Grouping, so the Gross Margin values are sorted within their Region groupings.