backend_helper.rb

  def role_and_tier_names(user)
    role_name = I18n.t("backend.users.index.role.#{user.account.role}")
    res = if user.tiers
      tier_names = user.tiers.map(&:name).join(", ")
      I18n.t("backend.role_and_tier_names", role: role_name, tier_names: tier_names)
    else
      role_name
    end

    content_tag(:span, res, class: "role-and-tier-names").html_safe
  end