To show the corresponding region when users hover their mouse over any of the bars, you need to drag Region to Tooltip on the Marks card. This will add Region as a field in the tooltip text that appears when users hover over a mark. You can also customize the tooltip text by editing it in the Tooltip dialog box. Reference: https://help.tableau.com/current/pro/desktop/en-us/buildmanual_shelves.htm https://help.tableau.com/current/pro/desktop/en-us/formatting_tooltips.htm