Files in computers are increasing in number, so we require file management tools to find target files and to classify large groups of files. Our research group has been developing a system that provides virtual directories made up of related files. Many methods to extract inter-file relationships are available, such as word frequency, access co-occurrence, and so on. In practice, users need to select and combine multiple types of inter-file relationships to form groups of files they want. For this purpose, we propose FileSearchCube, a tool for file group analysis that introduces the data-cube concept. FileSearchCube provides cube operations for a set of files, and helps users to find relevant file groups.