1. Install coo with downstream FBC image: quay.io/redhat-user-workloads/cluster-observabilit-tenant/coo-fbc-v4-17:23da793a46da048edddbcdf2443d4461ba1fce06

For step 2-4, you can also execute automation 

TestMonitoringStackController/Prometheus_stacks_can_scrape_themselves_and_web_UI_works

2. create monitoringstack

apiVersion: monitoring.rhobs/v1alpha1
kind: MonitoringStack
metadata:
  name: self-scrape
  namespace: e2e-tests
spec:
  alertmanagerConfig:
    disabled: false
  logLevel: info
  prometheusConfig:
    replicas: 2
  resourceSelector: {}
  resources: {}
  retention: 120h 

3. create port-forward

oc -n e2e-tests port-forward service/self-scrape-prometheus 9090:9090

4. query metric from browser, refer screenshot