Yes, it is possible. The monitor has HDMI and DisplayPort connections. HP G5 docking is easily compatible. Connecting a second monitor to the HP G5 is also no problem. It does not matter which brand and type. The important thing is that the source device (notebook) really delivers the appropriate graphics performance. One tip is to make 100% sure that the connection cables (DP, HDMI) work before you set up your set up.
Connecting two monitors works if the docking solution can control two screens. However, the U2718Q model does not have a daisy chain option for connecting via DisplayPort.