How can I use Hugo engine render special file under custom style?

Recently, I had use the Hugo engine to rebuild my blog site. Then I meet a trouble that there can output a special file which I want to create the indexes from all pages. I want it was XML formatter file include each blog title, content, date and so on. So I had create the indexes.xml file into the layouts/_default folder, but after I run hugo -d command and I could not find it under the site root’s folder. I don’t known what’s wrong in this way, is someone can help me or give a suggest, thanks.

indexes.xml file content:

{{ printf "<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\" ?>" | safeHTML }}
  {{range where .Site.RegularPages "Section" "post"}}
    <title>{{ .Title }}</title>
    <url>{{ .Permalink }}</url>
      {{ range .Params.categories }}<category>{{ . }}</category>{{ end }}
      {{ range .Params.tags }}
      <tag>{{ . }}</tag>
      {{ end }}
    <content type="html"> {{ .Content | plainify }}</content>
  {{ end }}

Also I want build different search indexes files from different languages style. So which range I can switch and how can I do?