x1 is analogous to a sibling in a rank/seniority for/of a rirny'utka of x2 by standard/in hierarchy/via partial ordering or relation(ship) x3 (this is the connection between the rirny'utka at hand and x1 which justifies the treicytunba label), where x2 and the said rirny'utka are connected via intermediate steps x4 (ce'o).
An indirect ancestor (that is: the near-relation, sibling, or perhaps equal/contemporary of a direct ancestor) is included. The standard by which the direct ancestor (the rirny'utka) and x1 are equals/near-relations is x3; the meaning of/standard by which "ancestor" is meant is specified via relation(ship)s steps x4. See also: "dzena" (which is more general).