1. A computer-implemented system for displaying information, the system comprising: a data store for storing information about: category hierarchies associated with items, the category hierarchies constituting a first sub-portion of a product hierarchy, and attribute hierarchies including attributes, the attribute hierarchies constituting a second sub-portion of the product hierarchy, the category hierarchies being distinct in the product hierarchy from the attribute hierarchies; a rules engine associating the attribute hierarchies with the items in the category hierarchies according to attribute assignment rules, wherein each attribute in each attribute hierarchy includes at least one attribute value; and a server computing device for generating a hierarchical user interface (“UI”) wherein the server computing device: identifies at least two attribute hierarchies which have been associated with the items in the category hierarchies by the rules engine, each attribute in each identified attribute hierarchy containing at least one attribute value associated with the items in the category hierarchies; determines a prioritization of individual attribute hierarchies within the identified at least two attribute hierarchies; and determines a subset of the identified at least two attribute hierarchies, the determination based at least in part on the determined prioritization; wherein the UI includes: a representation of the category hierarchies; and a representation of the determined subset of the identified at least two attribute hierarchies; and wherein the server computing device, in response to a selection of an attribute value, causes: removal from the UI of representation of items not associated with an attribute having the attribute value, removal from the UI of at least one attribute hierarchy of said subset, said at least one attribute hierarchy determined based at least in part on the determined prioritization of the individual attribute hierarchies within the identified at least two attribute hierarchies, and display in the UI of representation of items associated with the attribute having the attribute value.