Contact Groups can allow you to retrieve a list of Eligible Officials or Ineligible Officials from within the Assigning Window and filter that list down to just a specific sub-group of officials in your organization. Once you have created one or more Contact Groups, you can use the group filter option in the Assigning Window to change which group you're viewing.
Additionally, if you always wish to start your assigning session with the same Contact Group, you can change the default group initially used by editing this in your Personal Profile under the Preferences tab.