The figure shows the "Add Resource to Group - Virtual Address" screen. There are two main areas on the screen: Network and Virtual Address.
In the Network area:
The option "Show networks accessible by clients" is selected.
For Network, "Public" is selected.
Subnet Address and Subnet Mask are filled in for you, and cannot be edited.
In the Virtual Address area:
Host Name is set to the virtual hostname ("vhost" in this case).
IP Address is set to the IP for the virtual hostname ("188.8.131.52" in this case).