RadGridView group only for groups with more than 1 item

[Mon]

Hello everyone,

I need your help. I want (like in title) group items in RadGridView, but if some group have exactly one item then I don't want group this item.
I use this part of code to group my item list.

<telerik:RadGridView.GroupDescriptors>
    <telerik:GroupDescriptor Member="Source"/>
</telerik:RadGridView.GroupDescriptors>

I want to achieve solution like this:

>group_1
       element_1
       element_2
>group_2
       element_3
       element_4
element_5  (because in group_3 we have only one item)
element_6  (because in group_4 we have only one item)
>group_5
       element_7
       element_8
       element_9

 

Thank you for your help.

Mon