I'm using a linq group by query (with two grouping parameters) and would like to use the resulting data in a nested repeater.

var dateGroups = from row in data.AsEnumerable()
    group row by new { StartDate = row["StartDate"], EndDate = row["EndDate"] };

"data" is a DataTable from an SqlDataAdapter-filled DataSet. "dateGroups" is used in the parent repeater, and I can access the group keys using Eval("key.StartDate") and Eval("key.EndDate").

Since dateGroups actually contains all the data rows grouped neatly by Start/End date, I'd like to access those rows to display the data in a child repeater.

To what would I set the child repeater's DataSource? I have tried every expression in markup I could think of; I think the problem is that I'm trying to access an anonymous member (and I don't know how.) In case it doesn't turn out to be obvious, what would be the expression to access the elements in each iteration of the child repeater?

Is there an expression that would let me set the DataSource in the markup, or will it have to be in the codebehind on some event in the parent repeater?