How to enable showMultiCluster for Grafana Dashboards?

[rgarcia89]

Hi, I am currently creating a PoC for pushing metrics (remoteWrite) of multiple Prometheus to a central one (enableRemoteWriteReceiver) for centralised visualization in Grafana. So far everything works fine. However per default if the showMultiCluster is not set to true for the following mixin (https://github.com/kubernetes-monitoring/kubernetes-mixin#multi-cluster-support) from which the dashboards are coming the cluster variable in the dashboards stays hidden (https://github.com/kubernetes-monitoring/kubernetes-mixin/blob/master/dashboards/apiserver.libsonnet#L228).

Here comes my problem - I don't know in which section to add this argument to my jsonnet which is based on this one (https://github.com/prometheus-operator/kube-prometheus/blob/main/docs/customizing.md#generating)

[rgarcia89]

done via #1859