French to English Social Sciences Management family business succession

Below a paragraph talking about the decreasing role of the predecessor's advisor and the growing role of the successor's adviser.

inserer la figure 2 sur le biseau

from what I can gather of the translation of the word "biseau" in the Larousse (bord taillé obliquement, et non à angle droit), this is a figurative use of the word

I have found a translation that seems to correspond, namely "on the wane", but the context doesn't fit so I am hesitant to use it.

SafeTex, Philgoddard and rkillings, I am particularly interested to see if you will comment as I found your contributions very useful yesterday. thanks again.