Introduced in build 8.4
ShowValueAsproperties of a PivotTable.
showValueAsThe type of ShowValueAs described by ShowValueAsType.
baseFieldThe base field for comparisons.
baseItemIndexThe index of the base item for comparisons
This property cannot be set on ValuesLabels. You can check if a PivotField is calculated field with the IsValuesLabel Property
This is the same as going to Value Field Settings > Show values as.
SetShowValueAs(), certain ShowValueAsTypes use a source field as a base field and an index for one of the values in the data source column associated with the source field. The base field and value specified by the base item index are used to compute the values shown in the PivotTable.