A C1ListViewControlGroupItem set to 'radiolist' will appear as a radio button item.

The markup used to create the radio list above resembles the following:

<cc1:C1ListViewControlGroupItem ControlGroupType="radiolist" LabelText="Priority">
     <innerlistcontrols rows="1" width="400px">
        <asp:ListItem>1</asp:ListItem>
        <asp:ListItem>2</asp:ListItem>
        <asp:ListItem Selected="True">3</asp:ListItem>
        <asp:ListItem>4</asp:ListItem>
        <asp:ListItem>5</asp:ListItem>
      </innerlistcontrols>
</cc1:C1ListViewControlGroupItem>