hugo-theme-relearn/layouts/shortcodes/relref.html

{{- if in (.Get 0) "/_index.md" -}}
    {{- $paths := (split (.Get 0) "_index.md") -}}
    {{- $pagepath := index $paths 0 -}}
    {{- $anchor := index $paths 1 -}}
    {{- with .Site.GetPage "section" (trim $pagepath "/") -}}
        {{- ( printf "%s%s" $pagepath $anchor ) | relLangURL -}}
    {{- end -}}
{{- else -}}
    {{- with .Site.GetPage "section" (.Get 0) }}
        {{- .RelPermalink -}}
    {{- else -}}
        {{- .Get 0 | relref .Page -}}
    {{- end -}}
{{- end -}}