1. A computer-implemented method for reducing number of options presented to a user where the options have characteristics that are arranged in a multi-dimensional hierarchical space, said method comprising: identifying common dimensions using dimension nodes in dimensional points; identifying compatible nodes for each dimension in the multi-dimensional hierarchical space by determining whether an association exists; generating compatible pairs of surviving points after applying each of the compatible nodes from the common dimensions; computing greatest lower bounds (GLBs) for each of the generated compatible points; generating a set of options comprising points from the generated compatible points and the computed GLBs; upon login of the user, applying user-specific information to select a user subset of the set of options; wherein the user subset includes the computed GLBs and the compatible points that are consistent with the user-specific information; and displaying the selected user subset of options to the user for selection by the user.