The term 'Narrowed Down' can be described as having been 'Tapered'. This means that the size or scope of something has been reduced or made smaller. This could refer to a physical object, such as a piece of wood that has been cut into a tapered shape, or it could refer to a concept, such as a list of items that has been narrowed down to only the most important ones. In either case, the result is a reduction in size or scope.