Hi Simon,
How would you expect such functionality to be exposed, considering that the listview has no rendering of its own? How would, for example, a grouping operation be invoked? I am asking this so we have better context of your expectations.
In the meantime, you might be able to use a grid that already has grouping: https://docs.telerik.com/blazor-ui/components/grid/grouping
Regards,
Marin Bratanov
Progress Telerik