Hi,
I downloaded the project and tried to fix metadata.xml somehow to get it to work but I could not do so. Sorry.
Basically I think if you would like to have the structure directly in one object you have to adapt metadata.xml to something like this:
<Property Name="ChildrenDirect" Type="Collection(Self.OrgUnit)" Nullable="true"/>
(This refers to your question "I have Root Bank and Child Bank in different objects while I expect to have one object as a property of another.")
As far as I know if you have a navigation property you will always have different entity sets / object lists.
But sorry, I could not find a solution for recursive entities.
Best regards,
Sebastian