Nested object logstash not parsing correctlly

[miiroslavkardos (Miroslav Kardos)]

Hello , can u help me solve the issue.
I have nested object "host" => { "name" => "myserver" } like below

"cluster" => "xxx-logs",
 "name" => "xxx2",
 "component" => "xxx",
                **"host" => {**
**        "name" => "myserver"**
**    },**

If i want to parse it with mutate filter and replace like this :

 mutate {
                replace => {"host" => "%{[host][name]}"}
                }

I got correct value "host" => "myserver" with output to console like this :

utput {
                stdout {
                codec => rubydebug
                       }

BUT ....
If I send it to kibana i got this :
host %{[host][name]}

What am i doing wrong?
Index field type is text. in index template