What is best way to connect a Dell U2722 to desktop tower and WD19TB latop dock? I want to leave both permanently connected.

Does the Dell U2722 connect to two DisplayPort sources? Or is the second DisplayPort only for daisy chaining? I have U2722 connected to a desktop tower using DisplayPort. I also want to connect it to my WD19TB dock using DisplayPort. Can I connect the desktop and dock to the monitor and switch back and forth? Or do I need to use DisplayPort for the desktop and HDMI for the dock?