To output the object(s) that contain the current object’s or relationship’s symbol use:

containers

which answers the objects whose representations contain the first (from back to front) representation of the current object or relationship, in the oldest diagram representation of the current graph. The elements are sorted by area (smallest first), then by normal sorting order (type, id, oid).

Similarly, to output the objects contained in the current object’s symbol use:

contents

The elements are sorted by area (largest first), then by normal sorting order (type, id, oid).