I was looking at the stickied tutorial for modding, and it mentions that you have to point to the expansion directory to work with those files.
Ashes of Malmouth Integration
If you have the Ashes of Malmouth expansion you will have to do a few additional steps in order to be able to work with the expansion files. As mentioned before, there are two more fields “Additional Browse Directories” and “Additional Source Directories”. The additional browse directories field enables the Asset Manager to read additional database record files from a seperate .arz file while the additional source directory provides the Asset Manager with additional resource files for the resources browser window.
So there’s two expansion folders, but only one field for “Additional Browse Directories” and one field for “Additional Source Directories”. I’m assuming since the fields have a plural label, you can add multiple directories to it, but what exactly is the syntax for this?