Include non child relations in Editor

Hello, 

I have the following hierarchical Model (of entities and relations).

Root-Node: Model

Model contains 0..N Entities as children, called entities

Each Entity contains 0..N Relations as children, called relations

Each Relation points to an Entity, called target

So far no problems in creating the structure, the model, the generator and so on.

Now I would like to show the "incoming" relations on Entity-Level: I want to show in the editor for a given entity (this) the list with the following relations: this.parent:Model.entities.relations.where(r => r.target == this). This should be done by the already exisiting Concept Editor for "Relation" or better, by using a dedicated Editor Component for the inverted relation.

This may very well be read-only, the user can change the relations on the "owning" side. Unfortunately, "list" cannot access a behavior function, only the children, "read only model access" cannot deal with a list (except for producing a long string from the elements of the list) and "custom" is mostly undocumented unfortunately.

Thank you for your help,

Tun