When adding a new Hyper-V Host via the Hyper-V Host Wizard, the search filter returns no results.
When adding a new Hyper-V host, the AD Search filter returns no results when using the first letter of the Hyper-V host name plus a wildcard (*).
If the server is domain joined and then the Hyper-V role is added then the Hyper-V host name will not be picked up by the filter when you click refresh.
The server must have the Hyper-V role installed prior to being domain joined in order for the SPN's to be set correctly, and to be picked up by the filter. To work around this issue, clear the filter so that all the domain servers will be returned, at which point you can navigate through the domain to locate the desired Hyper-V host.