rirny'utka lujvo

x1 raises/is a mentor to someone who raises/is a mentor to someone who raises/is a mentor to [...] to someone who raises/is a mentor to x2 via intermediate steps x3 (ce'o).

Can be used for 'PhD advisor ancestry'. Usage of mixed standards of raising/mentoring telationship is possible; thus, the parent of the PhD advisor of one's parent is a form of rirny'utka to oneself. This is a broader notion of ancestorhood than is "ginlazdze".

In definition:

rirny'utka zei treicytunba
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).

In notes:

ginydze
x1 is a genetic/biological ancestor (or familial peer thereof) of x2 by relationship/to degree x3 through/along graph-geodesic within their shared biological family.