Using repetitive blocks in global or as variable in alertmanager.yml config file

Question

I have to send different alerts in 20 Slack channels based on some filter. My Alertmanager config file looks like (only two receiver as example):

global:
  resolve_timeout: 1m
  slack_api_url: '<slack_api_url>'
 
templates: 
  - 'slack_alert.tmpl'

route:
  receiver: 'slack-admin'
  routes:
  - receiver: 'slack-ch1'
    matchers:
      - machine_group =~ ".*something1.*"
    continue: true
receivers:
  - name: 'slack-admin'
    slack_configs:
    - channel: '#slack-admin'
      send_resolved: true
      icon_url: https://avatars3.githubusercontent.com/u/3380462
      title: '{{ template "slack.slack_alert.title" .}}'
      text: '{{ template "slack.slack_alert.text" .}}'

  - name: 'slack-ch1'
    slack_configs:
    - channel: '#slack-ch1'
      send_resolved: true
      icon_url: https://avatars3.githubusercontent.com/u/3380462  
      title: '{{ template "slack.slack_alert.title" .}}'
      text: '{{ template "slack.slack_alert.text" .}}'

Is there any way to declare following block of code as global variable without tasting to al 20 channels?

      send_resolved: true
      icon_url: https://avatars3.githubusercontent.com/u/3380462  
      title: '{{ template "slack.slack_alert.title" .}}'
      text: '{{ template "slack.slack_alert.text" .}}'

Slack alert template is in Go templating form. Is it possible to integrate it with template?