Dimension Limits > Total can show a Tota bar in a bar chart.
Dimension Limits > Total can change the Label for the Total row
Expressions > Total mode allows different aggregations of count, max etc.
The Dimensions Limits Other and Total sections used to be on the Presentation properties, and form an odd collection of properties. For instance, the Presentation properties for a bar chart still show a checkbox for adding a scroll bar that includes the maximum number shown, which should probably also be on the dimensions Limits properties.