getSubNodePane().getChildren().clear();
chart.setRequiresLayout(true);
chart.requestChartLayout();
} else {
//make a new filter intersecting the global filter with text(description) and type filters to restrict sub-clusters
final Filter combinedFilter = Filter.intersect(new Filter[]{new TextFilter(event.getDescription()),
new TypeFilter(event.getType()),
chart.getFilteredEvents().filter().get()});
//make a new end inclusive span (to 'filter' with)
final Interval span = event.getSpan().withEndMillis(event.getSpan().getEndMillis() + 1000);