Bug 132515 Expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error
Description: Add an expression like "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" is return an error.The nesting "Toltal" seem not to be work. Step to reproduce: 1.new a datasource and dataset 2.drag the dataset to layout veiw for a table 3.set a group on the table 4.Insert a data into the group header with the expression e.g. "Toltal.rank(Tolta.ave(row[a]),ture,Null,1)" Actual result: An error was thrown out Expected result: It should work correctly in order to support some requirments
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/group/GroupInstanceFilter.java
* @throws DataException
	 */
	public void doGroupFiltering( Context cx )
			throws DataException
	{
		List groupLevels = new ArrayList( );
		List expressionList = new ArrayList( );
		populateGroupFilteringExpressions( expressionList, groupLevels );
		if ( expressionList.size( ) > 0 )
		{
			this.groupProcessor.calculateExpressionList( expressionList,
					groupLevels,
					IExpressionProcessor.FILTER_ON_GROUP_EXPR );
			
			ArrayList[] groupBoundaryInfos = this.groupProcessor.getGroupCalculationUtil( )
					.getGroupInformationUtil( )
					.getGroupBoundaryInfos( );
			populateFiltersInGroupBoundaryInfoSets( cx, groupBoundaryInfos );
			groupBoundaryInfos = this.groupProcessor.getGroupCalculationUtil( )
					.filterGroupBoundaryInfos( groupBoundaryInfos );
			OrderingInfo odInfo = this.groupProcessor.getGroupCalculationUtil( )
					.getGroupInformationUtil( )
					.getOrderingInfo( groupBoundaryInfos );
			this.populator.reSetSmartCacheUsingOrderingInfo( odInfo );
		}
	}
	/**
	 * Populate the Group filter expression list and its corresponding group
	 * level list that being used in IExpressionProcessor.calculate() method.
	 *