Advanced CATaloguer Pro supports a folder hierarchy consisting of a Desktop, Groups and Disks. The Desktop is at the top of the hierarchy. The desktop can contain Groups and Disks. This folder can be selected in the 'Look In' box in the Search pane to base a search on one part of the hierarchy. Groups and Disks can be moved from one part of the hierarchy to another by drag and drop, so you can organize the catalogue to optimize your frequent searches.

Groups contain Disks but have no direct relationship with the disk data. Groups are useful for grouping Disks to allow all Disks in a group to be searched without searching other groups.

A Disk is mapped to a base folder on a physical disk or partition, which need not be the root folder of the partition. All subfolders and files at all levels below the base folder have their counterparts in the catalogue as subfolders and files of the Disk. Thus the entire folder tree is visible in the catalogue, whether or not the physical volume is mounted. A Disk is not changed automatically when the corresponding data on the physical volume is changed. The user must perform a Synchronize operation on the catalogue to make the folder trees match again.