Gateway entityset with nested tables

Hi,

My requirement is to create a Gateway service to retreive material data + grid values (size and color) + stock for each grid value.

Level 1: Material general data

     Level 2: Grid values (nested table)

          For each line of level 2: Level 3: ATP stock (nested table)

In XML this is what I am trying to do:

<MATERIAL1>     <MAKTX>     <GRIDVALUES>          <GRIDVALUE1>               <GRID_VALUE_ATTRIBUTE1>               <GRID_VALUE_ATTRIBUTE2>               <STOCK_DATA>                    <STOCK_ATTRIBUTE1>                    <STOCK_ATTRIBUTE2>                    <STOCK_ATTRIBUTE3>  </STOCK_DATA>  </GRIDVALUE1>  </GRIDVALUES></MATERIAL1><MATERIAL2>     <MAKTX>     <GRIDVALUES>          <GRIDVALUE1>               <GRID_VALUE_ATTRIBUTE1>               <GRID_VALUE_ATTRIBUTE2>               <STOCK_DATA>                    <STOCK_ATTRIBUTE1>                    <STOCK_ATTRIBUTE2>                    <STOCK_ATTRIBUTE3>  </STOCK_DATA>  </GRIDVALUE1>  </GRIDVALUES></MATERIAL2>

I would like to get all these information in a single get_entityset request (taking filters in input request).

Whats is the best way to create such a service ? Do I need to use the complex entities ? Are there any samples around because I was not able to find anything on SCN.

Any advises on similar cases would be much appreciated.

Thanks in advance.

Thibault