The DocKtor is often asked how to add a third, fourth, or more external monitors. This can be done with a dock plugged into a dock, and while this is possible, it not economical or technically friendly. Many host platforms do not support beyond three monitors, especially high resolution monitors well.
That being said, it is possible.
Many of the Targus DisplayLink based docking stations, models DOCK1XX, can be connected to each other. i.e. A DOCK180 can be connected into another DOCK180 and it connected to the host PC for four 4K2K p60 monitors. However, this will most likely saturate the graphics capabilities of the host laptop.
This is not possible with the DOCK410 because of the limits of the DisplayPort Technology. However, it is possible to plug a DisplayLink based docking station into a DOCK410 USB port. i.e. a DOCK1XX plugged into the DOCK410 plugged into the PC.
Many people use the DOCK110 or DOCK120 for these since they are the most cost effective for the application and use a DOCK180, DOCK410, DOCK177 or DOCK171 for the host connection to supply host charging and power in addition to the multiple monitors.