The Top N Filtering is the best option when you want to filter elements that have the highest values from a random list. FlexPivot also provides Bottom N Filtering to filter elements with the lowest values. A good example can be using Top N or Bottom N Filtering to display the top-selling or bottom-selling products for analyzing the sales performance.

Top N Filtering with Code

In FlexPivot, you can apply Top N Filters using the PivotFilter class, which provides the TopNValueField property to select a value field, the TopNRule enumeration to choose between the top N or bottom N elements, and the TopN or BottomN properties to assign the number of elements to be filtered.

' Apply top n filtering
        Dim filter As C1.FlexPivot.C1FlexPivotFilter = fp.Fields("ProductName").Filter
        filter.Clear()
        filter.TopNValueField = fp.Fields("Quantity")
        filter.TopNRule = C1.FlexPivot.TopNRule.TopN
        filter.TopN = 3

// Apply Top N Filter
C1.FlexPivot.C1FlexPivotFilter filter = fp.Fields["ProductName"].Filter;
filter.Clear();
filter.TopNValueField = fp.Fields["Quantity"];
filter.TopNRule = C1.FlexPivot.TopNRule.TopN;
filter.TopN = 3;

Top N Filtering at Runtime

To display top N filtering at runtime:

1. Right click a field name. Click the Field Settings option to open the Field Settings dialog. This invokes the Field Settings dialog.
2. Select the Top N option in the filter dropdown menu.
3. In the TopN dialog, you can choose between TopN or BottomN and assign the number of elements to be filtered. You can also assign a value field in the by value option.