all you need is to tie the group to a different item in your model
@Html.RadioButtonFor(x => x.Field1, "Milk")
@Html.RadioButtonFor(x => x.Field1, "Butter")
@Html.RadioButtonFor(x => x.Field2, "Water")
@Html.RadioButtonFor(x => x.Field2, "Beer")
all you need is to tie the group to a different item in your model
@Html.RadioButtonFor(x => x.Field1, "Milk")
@Html.RadioButtonFor(x => x.Field1, "Butter")
@Html.RadioButtonFor(x => x.Field2, "Water")
@Html.RadioButtonFor(x => x.Field2, "Beer")