code: public void filterReset() {
          if (displayerSettings.isFilterEnabled()) {
  
              List<DataSetGroup> groupOpList = new ArrayList<DataSetGroup>();
              for (String columnId : columnSelectionMap.keySet()) {
                  DataSetGroup groupOp = dataSetHandler.getGroupOperation(columnId);
                  groupOpList.add(groupOp);
  
              }
              columnSelectionMap.clear();
  
              // Notify to those interested parties the reset event.
              if (displayerSettings.isFilterNotificationEnabled()) {
                  for (DisplayerListener listener : listenerList) {
                      if (currentFilter != null) {
                          listener.onFilterReset(this, currentFilter);
                      }
                      listener.onFilterReset(this, groupOpList);
                  }
              }
              // Apply the selection to this displayer
              if (displayerSettings.isFilterSelfApplyEnabled()) {
                  boolean applied = false;
  
                  if (currentFilter != null) {
                      if (dataSetHandler.unfilter(currentFilter)) {
                          applied = true;
                      }
                  }
                  for (DataSetGroup groupOp : groupOpList) {
                      if (dataSetHandler.drillUp(groupOp)) {
                          applied = true;
                      }
                  }
                  if (applied) {
                      redraw();
                  }
              }
              if (currentFilter != null) {
                  currentFilter = null;
              }
          }
      }
docs: Clear any filter.