If you don't define GroupName
for radio buttons, then they will group themselves according to their parent container, i.e. all radios in a single stack panel/grid/dock panel will behave as if they have the same group name. Can you change your UI so that all buttons will reside in the same container?
If that is not possible, define a property of type String
on your user control and then bind GroupName
(on each radio button) to that property
GroupName="{Binding RelativeSource={RelativeSource FinsAncestor, AncestorType={x:Type my:MyUserControl}}, Path=CurrentGroupName}"
Then, on each instance of the user control, you can set a different group name.