Nested repeat - need outer index value inside inner repeat

I can't use variables because they are not supported in the version of orbeon
> i am using.
>
> I have tried -  index('outer-repeat')
>
> but this just returns the inner repeats index.
>
> Does this actually work?  The documentation seems to say it does but it
> doesn't seem to.


Is it possible to store the position() of the outside loop in the model and use it in the inner loop?

Any ideas would be great.  Thanks.