You should look for this change in the coming hotfix. I’ll add the relevant hotfix note here for additional clarity.
- Asset Manager will now add additional build and source directories to Import Record, allowing modders to import expansion files. If using default paths, Additional Source Directories should be set to C:\Program Files (x86)\Steam\steamapps\common\Grim Dawn\mods\gdx1\ and Additional Browse Directories to C:\Program Files (x86)\Steam\steamapps\common\Grim Dawn\gdx1\