Working with the legend
A legend is a key to the items in the visualization. The legend appears if there's a column in the Color data slot or Size by data slot.
If there are too many items to be displayed in the legend, an ellipsis is displayed.
When you move the mouse pointer over an item in the legend, key information is displayed in a tooltip, including the item's name and the overall measure summary for that item. If the measure used in the visualization is based on a calculation that uses the setting Calculate after Aggregation, then N/A will be displayed in the tooltip (as shown in the following image) because this type of aggregation is currently not supported in the legend.