How should I modify logstash.conf to get the field I want?

[wangyu]

I use the ELK + Filebeat , all version is 6.4.3 , the OS is windows 10

I add custom field in filebeat.yml , the key name is log_type , the value of log_type is nginx-access

The picture show part of filebeat.yml.

The content of logstash.conf is :

input {
    beats { 
       host => "0.0.0.0"
       port => "5544"
  } 
} 

filter {

mutate { 
  rename => { "[host][name]" => "host" } 
}	

if [fields][log_type] == "nginx-access" {
           grok {
                  match => { "message" => ["%{IPORHOST:[nginx][access][remote_ip]} - %{DATA:[nginx][access][user_name]} \[%{HTTPDATE:[nginx][access][time]}\] \"%{WORD:[nginx][access][method]} %{DATA:[nginx][access][url]} HTTP/%{NUMBER:[nginx][access][http_version]}\" %{NUMBER:[nginx][access][response_code]} %{NUMBER:[nginx][access][body_sent][bytes]} \"%{DATA:[nginx][access][referrer]}\" \"%{DATA:[nginx][access][agent]}\" \"%{DATA:[nginx][access][x_forwarded_for]}\" %{NUMBER:[nginx][access][request_time]}"] }
           }
	
mutate {
     copy => { "[nginx][access][request_time]" => "[nginx][access][requesttime]" }
  }
			
mutate {
    convert => {
      "[nginx][access][requesttime]" => "float"
    }
  }
}
}

output {
      stdout { 
      codec => rubydebug { metadata => true }
      }
  
      elasticsearch { 
	    hosts => ["localhost:9200"] 
      } 
    }

When I use the command :

logstash.bat  -f  logstash.conf

The output is :

Question 1：

The field in the red box above is "requesttime" and "request_time" , what I want the field is nginx.access.requesttime and nginx.access.request_time，not requesttime and request_time 。 How should I modify logstash.conf to achieve my goal?

Question 2:

When I use the above logstash.conf , the field of the kibana management interface is only "request_time" field .

The picture show this :

If I want the "requesttime" field to also appear in the fields of the Kibana management interface, how should I modify the logstash.conf ?