hugo-theme-hilfe/layouts/shortcodes/tab.html

{{- if .Parent }}
  {{- $name := .Get 0 }}
  {{- $group := printf "tabs-%s" (.Parent.Get 0) }}

  {{- if not (.Parent.Scratch.Get $group) }}
    {{- .Parent.Scratch.Set $group slice }}
  {{- end }}

  {{- .Parent.Scratch.Add $group (dict "Name" $name "Content" .Inner) }}
{{- else }}
  {{ errorf "%q: 'tab' shortcode must be inside 'tabs' shortcode" .Page.Path }}
{{- end }}