To set up combining of several values of fixed dimension elements, use the Data group of parameters on the side panel:
To open the Data group of parameters

Set the Aggregation of Fixed Dimensions parameter.
Aggregation enables the user to combine values of elements selected in fixed dimensions.
To set aggregation, select the method in the drop-down list:
None. No aggregation is executed. Default value.
Sum. Default value. Values of fixed dimensions elements are summed.
Minimum. Minimum value is selected for fixed dimension elements.
Maximum. Maximum value is selected for fixed dimension elements.
Arithmetic Mean. The average of fixed dimension elements is determined considering empty values.
See also:
Setting Up Data Visualization | Setting Up the Table Visualizer