There are interesting arrangements of magnets that can strengthen the field in some places while weakening it in others. This is discussed in
https://physics.stackexchange.com/questions/17200/can-magnetic-fields-be-redirected-and-focused-at-one-point and examples are the solenoid, the Halbach array, and an iron cone.

However, these all appear to be limited in their range. In contrast, light can be focused at a distant point, for example with a magnifying lens. A laser beam can be focused such that its reflection on the Moon can be detected. We can communicate with Voyager 1 at 130 AU.

Is it possible to focus a magnetic field such that it would be able to, say, move a nail from a kilometer away? If not, what is the fundamental difference between light and magnetic field that is responsible for this limitation?