SYMPTOM:
In attribute editor, when trying to add parent attributes, the expected parent attribute is not listed in the parent candidates.
CAUSE:
The reason why the attribute is not listed as parent candidate is that there is no relationship table found to define the hierarchy structure, which stores the hierarchical relationship between the elements of parent and child attributes.
ACTION:
Create relationship table to define the hierarchical organization of the two attributes or add a new parent attribute field in the look up table of child attribute.
