code: @Override
      public void onFilterEnabled(Displayer displayer, DataSetGroup groupOp) {
          String firstColumnId = dataSet.getColumnByIndex(0).getId();
          List<Integer> currentFilter = super.filterIndexes(firstColumnId);
  
          // If selector is active then ignore external filters.
          if (currentFilter.isEmpty()) {
              if (firstColumnId.equals(groupOp.getColumnGroup().getColumnId())) {
                  columnSelectionMap.put(groupOp.getColumnGroup().getColumnId(), groupOp.getSelectedIntervalList());
              }
              super.onFilterEnabled(displayer, groupOp);
          }
      }
docs: KEEP IN SYNC THE CURRENT SELECTION WITH ANY EXTERNAL FILTER