[+phx:if=`UltimateParent`:is=`10`:then=`10`:else=`11`+]
[[if? &is=`[*parent*]:in:10` &then=`10` &else=`11`]]
This question has been answered by iusemodx. See the first response.
[[if? &is=`[[UltimateParent]]:in:10` &then=`10` &else=`11`]]
[[UltimateParent:is=`8`:then=`8`:else=`11`]] <!--@IF:[[UltimateParent:is=8]]> 8 <@ELSE> 11 <@ENDIF-->