For convenience, you can combine materials within the separate catalogs for each group of materials. To create a new catalog you need to select library, in which it will be created, press and select Create Catalog item from the context menu. Created category will be called New Catalog. You can rename catalog directly after creation or rename it later using Rename item from the context menu.
Created category can be deleted using Delete item from the context menu.
To copy all materials from a catalog to the list of materials of the current model, use command Copy from the context menu or drag the category manually.
Within one library, you can create any number of catalogs. In each catalog, you can create additional folders with materials (sub-catalogs).
The catalog can be copied and transferred to another library or catalog.