mapping help

I have a scenario, where the source look like:

<ORDER>

<OrderDetails>

<OrderNumber>

..

..

</OrderDetails>

<RawMaterailDetails>

<RawMaterial>

<Qty>

</RawmaterailDetails>

<OperationDetails>

<OperationId>

..

..

</OperationDetials>

</ORDER>

I have Orderdetails occurring once and RawMaterailDetails and OperationDetials repeating.

Now I need to create a target structure looping on operationdetails and rawmaterialdetails.

For each order there are many Operations and for each operation there are many rawmaterials.So I need to create subelements for each operation and for each operation i need to create elements for rawmaterials.

Any help pls..

thankyou