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
* @return
	 */
	private void populateGroupFilteringExpressions( List expressionList,
			List groupLevels )
	{
		for ( int i = 0; i < this.populator.getQuery( ).getGrouping( ).length; i++ )
		{
			List groupFilters = this.populator.getQuery( ).getGrouping( )[i].getFilters( );
			if ( groupFilters == null )
				continue;
			for ( int j = 0; j < groupFilters.size( ); j++ )
			{
				expressionList.add( ( (IFilterDefinition) groupFilters.get( j ) ).getExpression( ) );
				groupLevels.add( new Integer( i + 1 ) );
			}
		}
	}
	/**
	 * Populate the "accept" fields in GroupBoundaryInfos. If one
	 * GroupBoundaryInfo would be filtered out then the "accept" field is set to
	 * false else ture.
	 * 
	 * @param cx
	 * @param groupBoundaryInfos
	 * @throws DataException
	 */
	private void populateFiltersInGroupBoundaryInfoSets( Context cx,
			ArrayList[] groupBoundaryInfos ) throws DataException
	{
		for ( int i = 1; i <= this.populator.getQuery( ).getGrouping( ).length; i++ )