Put clusters of bones into a specific [Destruction] level

I’m creating a complex Geometry Collection for destruction. Different ‘materials’ will be in this collection. I want wood to be at a lower level in the destruction hierarchy, so that it is destroyed more easily than stone components.

This is what I’m referencing when I use the term level:

My stone walls span from Level 0 (the hardest to destroy) with fragments extending into level 3 (the easiest to destroy). However I would like my wooden window frame to have all bones set to level 3 so that it is always easy to destroy.

Currently when I break down the window frame bone into smaller bones, their bones immediately go into level 2 making them as hard to destroy as my stone structures. I don’t know how to put the entire window frame into a lower destruction level and would like help to do so.

I’ve attached some images that I hope my make my question clearer.

Here is an example of the structure I am dealing with:

Here is the wooden frame, embedded in a stone wall that has already been decomposed into bones:

Here is a rough idea of how I might dissect that wooden window into wooden ‘splinters’, though it is placed in a destruction level that is too high: