Angular 9 – Webpack how does Chrome DevTools decide which folders to watch?

In an Angular 9 application I have 2 projects such as angular.json:

{
  //some config...
  "projects": {
    "mainProject": {//some config...},
    "custom-charts-lib": {//some config...}
  }
}

In development mode I end up with the following source map bundled by webpack :

enter image description here

I can debug as usual the src/ folder but any breakpoints I put in projects/custom-charts-lib/src/lib are ignored.

How does Google Chrome DevTools decide which folders to watch for breakpoints ? Does there is a way to add this folder to the "watch folders" or a webpack trick to make it work ?

Source: AngularJS Questions