For more information about group mappings see Group mapping and Transforms that create group mappings.
To create a new group mapping:
In the mapping routine area, drag a group on the source side (the source element) to a group on the target side (the target element). The target group must have same data layout as the source group.
The mapping editor creates a new mapping between the source element and the target element consisting of: (a) a new transform; (b) a connection from the source element to the transform; and (c) a connection from the transform to the target element.
The mapping editor also sets the transform to an appropriate default transform type (see Default transform type).