Hi,
With our libraries, we include a small script to add the texture path to 3DS Max automatically.
But according to your screenshot, this is a library from Vizpark, a third party creator.
Probably they don't include a similar script in their packages. This is optional, because each vendor may configure their libraries in different ways.
Besides this, Forest includes a mechanism to scan all libraries, searching for folders named 'maps', and add them to 3DS Max.
For performance reasons, in the latest releases this process is applied only to the builtin libraries, but not to the user libraries.
This may be configured at Library Browser->Preferences,as shown in the attached image.
Anyway, if you have already added the texture path manually, it's not necessary any further step.