There are some situations where it would be convenient to be able to retrieve the filter that was added to a query and then modify it (perhaps add more clauses). For example: CompassQuery query = ... // let's say we added some filters here // let's say someone else wants to add more filters CompassQueryFilter currentFilter = query.getFilter(); // This doesn't exist! CompassQueryFilterBuilder builder = session.queryFilterBuilder(); CompassQueryFilter additionalFilter = ... CompassQueryFilter newCompleteFilter = builder.bool().and(currentFilter, additionalFilter).toFilter(); query.setFilter(newCompleteFilter)