I don't know of any automatic option, but if you control the schema then you
need to make sure that all elements that were previously only defined tp be
nested elements are also valid as top-level elements. If you're using the
DataSet to generate the XML in the first place, can you extract some
"reference data" and extract the Schema you validate against from the
DataSet and then add the necessary top-level elements?

Signature
HTH
Christoph Schittko [MVP, XmlInsider]
Software Architect, .NET Mentor
> I'd like to know if there is support in .NET to
> somehow "flatten" a nested XML schema.
[quoted text clipped - 8 lines]
> nested flag to false and then be able to use it for
> validation.