fill_from_audit.rb

def interested_hostgroups
  Hostgroup.where(id: Katello::Hostgroup::ContentFacet.where(content_source_id: nil, kickstart_repository_id: nil, content_view_id: nil, lifecycle_environment_id: nil).select(:hostgroup_id))
end

def pick_facet_values(hg)
  facet_values = {}
  hg.audits.reverse.each do |audit|
    hg_changes = audit.audited_changes.slice("lifecycle_environment_id", "kickstart_repository_id", "content_view_id", "content_source_id")
    facet_values = hg_changes.merge(facet_values)
  end
  facet_values.map do |k,v| 
    v = v[-1] if v.is_a? Array
    [k, v]
  end.to_h
end

interested_hostgroups.each do |hg|
  hg.content_facet.update!(pick_facet_values(hg))
end