Filter Expression Use Cases.  

List memberNames = new ArrayList();
ExpressionInterface chevy = new StringExpression();
((StringExpression) chevy).setText("[CARS].[ALL CARS].[CHEVY]");
((StringExpression) chevy).setExpressionType(ExpressionTypes.EXP_TYPE_CHARACTER);
memberNames.add(chevy);
filterExpression = new MemberFilterExpression();
filterExpression.setWhatToCompare(tdi); <<== where tdi is CARS
filterExpression.setMemberNames(memberNames);
FilterItem filterItem = ds.newFilterItem();
filterItem.setExpression(filterExpression);
ds.addBusinessItem(filterItem);
List filterList = new ArrayList();
filterList.add(filterItem);
ds.setFilters(filterList);