Aria Operations view editor does not show expected objects as Ancestor/Descendant in the drop down despite this relationship being present for certain objects.
Aria Operations 8.18.5
The current behaviour is that the Ancestor and Descendant object lists for a random set of five objects of the selected type are retrieved.
If the relationship is not present for all of the objects of the selected type then it may not be shown in this list as an Ancestor/Descendant.
Engineering have been made aware of this behaviour and it will be changed in an upcoming release.