code: public void filterApply(String columnId, List<Interval> intervalList) {
          if (displayerSettings.isFilterEnabled()) {
  
              // For string column filters, init the group interval selection operation.
              DataSetGroup groupOp = dataSetHandler.getGroupOperation(columnId);
              groupOp.setSelectedIntervalList(intervalList);
  
              // Notify to those interested parties the selection event.
              if (displayerSettings.isFilterNotificationEnabled()) {
                  for (DisplayerListener listener : listenerList) {
                      listener.onFilterEnabled(this, groupOp);
                  }
              }
              // Drill-down support
              if (displayerSettings.isFilterSelfApplyEnabled()) {
                  dataSetHandler.drillDown(groupOp);
                  redraw();
              }
          }
      }
docs: Filter the values of the given column.
  
  @param columnId The name of the column to filter.
  @param intervalList A list of interval selections to filter for.