As each collection would be specific for each row, I am afraid that you need to define different instances of this collection for each row. So, more appropriate in this case would be to define a child collection for each item present in the source collection of RadGridView, populate it with the number of elements needed and bind the ListView's ItemsSource to it.
I prepared a small sample as a demonstration of the approach. I hope it fits your requirements.
Note however, that such approach of using the control is not quite appropriate. I suggest you taking a look at the RowDetails topic for more information on the recommended usage of RadGridView in such scenarios.
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