hugo-theme-hello-friend/layouts/partials/menu.html

<nav class="menu">
  <ul class="menu__inner menu__inner--desktop">
    {{ if or $.Site.Params.showMenuItems (eq $.Site.Params.showMenuItems 0) }}
      {{ range first $.Site.Params.showMenuItems $.Site.Menus.main }}
        {{ if not .HasChildren }}
          <li><a href="{{ .URL }}">{{ .Name }}</a></li>
        {{ end }}
      {{ end }}
      {{ if gt (len $.Site.Menus.main) $.Site.Params.showMenuItems }}
        <ul class="menu__sub-inner">
          <li class="menu__sub-inner-more-trigger">{{ $.Site.Params.MenuMore | default "Show more" }} <span class="menu__sub-inner-more-trigger-icon">></span></li>

          <ul class="menu__sub-inner-more hidden">
            {{ range last (sub (len $.Site.Menus.main) $.Site.Params.showMenuItems) $.Site.Menus.main }}
              {{ if not .HasChildren }}
                <li><a href="{{ .URL }}">{{ .Name }}</a></li>
              {{ end }}
            {{ end }}
          </ul>
        </ul>
      {{ end }}
    {{ else }}
      {{ range $.Site.Menus.main }}
        {{ if not .HasChildren }}
          <li><a href="{{ .URL }}">{{ .Name }}</a></li>
        {{ end }}
      {{ end }}
    {{ end }}
  </ul>

  <ul class="menu__inner menu__inner--mobile">
    {{ range $.Site.Menus.main }}
      {{ if not .HasChildren }}
        <li><a href="{{ .URL }}">{{ .Name }}</a></li>
      {{ end }}
    {{ end }}
  </ul>
</nav>