Range index, value where?

I’m trying to do the following :

{{ range  $key, $value := (where $.Site.Data.downloads "type" "==" "release") }}

Currently, I have the following code that works :

<h2>Beta versions</h2>
{{ range $key, $value := $.Site.Data.downloads }}
{{ if eq $value.type "beta" }}
<h3>{{ $key }}</h3>
OVA : <a href="https://xxx.xxx.xxx/dl/{{ $value.OVA }}">{{ $value.OVA }}</a> (md5 <code>{{ $value.MD5 }}</code>)<br>
Update : <a href="https://xxx.xxx.xxx/dl/{{ $value.UPDATE }}">{{ $value.UPDATE }}</a>
{{ end }}
{{ end }}

But it’s limited in the way that when there is no beta version, I am displaying the title anyway.

So I was trying to clean the code a bit and start with looping over the filtered list as the documentation seems to indicate it’s possible. The JSON is like the following :

{  
   "2.2":{  
      "type":"release",
      "OVA":"NAbox-2.2.ova",
      "OVALink":"http://xxx.xxx.xxx/dl/NAbox-2.2.ova",
      "UPDATE":"NAbox-2.2.tgz",
      "UpdateLink":"http://xxx.xxx.xxx/dl/NAbox-2.2.tgz",
      "MD5":"e49bfcb5ef81eb1cb317a6fd258bae73"
   },
   "2.1.5":{  
      "type":"release",
      "OVA":"ADVA-2.1.5.ova",
      "OVALink":"http://xxx.xxx.xxx/dl/ADVA-2.1.5.ova",
      "UPDATE":"adva-2.1.5.tgz",
      "UpdateLink":"http://xxx.xxx.xxx/dl/adva-2.1.5.tgz",
      "MD5":"d67291a132a5fd0b85f703d77997527f"
   }
}

Ideally, I would like to display a beta download section only if there is anything type=“beta”, same for the stable release.

Thoughts?