If filtering is applied to the current group, the ShowNewValues property specifies whether new field values (values that have been added to the datasource after the filter condition was set) are shown or hidden by default.
If filtering is not applied to the group, new field values are always displayed, regardless of the ShowNewValues property value.
The ShowNewValues property is also not in effect if hierarchical filtering is disabled for the current group (see PivotGridFieldOptions.GroupFilterMode). In this instance, use the PivotGridFieldBase.ShowNewValues properties of individual fields.
In Pivot Grid, end-users can enable or disable the ShowNewValues option via the
toolbar button.