Combined ISetProperty

Combined ISetProperty

Question
Is there a way to combine to ISetProperties together to get observable
flat superset implementing ISetProperty again?
Context
My model often looks like:
Parent
\Children
\Grandchildren
Being an EMF model it has ISetProperty for Children and Grandchildren of a
single Child.
I want to following GUI representations of the model.
A list of all Gradchildren for a Parent:
GrandchildA
GrandchildB
GrandchildC
GrandchildD
GrandchildE
A table of all Parents with a column containing all unique Grandchildren
Parent1 GrandchildA,GrandchildB
Parent2 GrandchildC,GrandchildD
Parent3 GrandchildE
Both should handle model updates.
Databinding
Jface dataproviders for these usecases have different interfaces and
implementations, model differ in details, so I've thought databinding will
help me to abstract over these.
For the first case it would be very nice to use
ObservableSetContentProvider if there was a way to get ISetProperty for
all Grandchildren for Parent.
For second case ColumnLabelProvider could create an IObservableSet to
watch Grandchildren of each parent in a similar way.