Bug 136270 Group's data binding column can only be used by the group itself
If you add some data binding columns to a group, these columns can only be used by this group itself. It should has a way to make the child can use the parent group's data binding column.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
}
		
		List availableList = new ArrayList( );
		for ( int i = 0; i < list.size( ); i++ )
		{
			if ( parent.canContain( slotId,
					( (IElementDefn) list.get( i ) ).getName( ) ) )
			{
				availableList.add( list.get( i ) );
			}
		}
		return availableList;
	}
	/**
	 * Get the containable element type list of give slot handle
	 * 
	 * @param slotHandle
	 */
	public static List getElementSupportList( SlotHandle slotHandle )
	{
		return getElementSupportList( slotHandle.getElementHandle( ),
				slotHandle.getSlotID( ) );
	}
	/**
	 * Gets the support list of the given parent element. The slotID is decided
	 * by the parent element.
	 * 
	 * @param parent
	 *            the parent element
	 * @return the the support list of the element