The view demonstrates access to the context object of a composition. In the scenario set up here, "worlds" can be created. Each world consists of a set of "things". The relation world to things is a composition. So each thing belongs to exactly one world. A thing can be needed for other things. This needs-relation is represented using a separate class because the relation is annotated with a reason. Each link object of the needs-relation belongs to exactly one thing (also a composition relation).

With the needs-relation, it must now be ensured that things of one world may only need things of the same world. Therefore, the selection of things in the needs-relation must be restricted to the things of the same world to which the thing for which a needs-link is created belongs. To do this, the context in which the link object is located must be accessed in the option provider for the "Thing" attribute of the needs-relation. This must be ensured both when creating a new link and when editing an existing link.