You can find this section in HostBill Admin Area → Settings → General settings → Domain & DNS → Domain Suggestions.
This option allows to you enable domain suggestions. You can:
This option lets you choose the suggestion engine
This option lets you define maximum number of suggested names per search.
This option lets you decide whether or not to include adult results. Please note that not all suggestion engines support this option.
Choose the TLDs that should be displayed in results. If nothing is selected the results will contain all suggestions from suggestion engine