To shorten and simplify the guided navigation paths that users must traverse to find the data that they are looking for, you can specify that a dimension value's refinements (children) be displayed in place of the dimension value itself, if the number of such refinements if less than or equal to a threshold value that you specify. A dimension value that can be replaced in a guided navigation path by its children is called a collapsible dimension value. All dimension values in a dimension except the root and the leaves can be made collapsible. You specify treshold values for entire dimensions, rather than for individual dimension values.