Filtering SharePoint Fields, has been a frustration for many SharePoint Administrators over the last few years, but finally there is a solution to the dreaded "Secondary Filter" issue.
Out of the Box SharePoint cannot handle column filtering and developing systems using SQL tables for each separate list is both expensive and time consuming.


Now, we have the answer in "Cascaded Lookup" a SharePoint add-on from SharePoint Boost which makes it easy to add the function to all lists in just a few minutes.
An example would be filtering a Country list by Continent, theses filters can now be cascaded to allow Cities to be filtered by State etc....