docs-v2/layouts/shortcodes/list-all-functions.html

{{ $currentVersion := (index (findRE "[^/]+.*?" .Page.RelPermalink) 0) }}
{{ $functionsPath := print "/" $currentVersion "/reference/flux/functions" }}

<ul>
{{ range where $.Site.RegularPages.ByTitle "Section" $currentVersion }}
  {{ if in .Title "() function"  }}
    {{ $title := replaceRE `\ function` "" .Title }}
    <li>
      <a href="{{ .RelPermalink }}">{{ $title }}</a>
    </li>
  {{ end }}
{{ end }}
</ul>