Divide groups with PromQL
You need to use the on() function as well. So it would be like this.
label_replace(sum(rate(container_cpu_usage_seconds_total{pod_name=~"rewe-bd-palantir-vernemq.*", container_name="vernemq"}[1m])) by (pod_name), "pod", "$1", "pod_name", "(.*)") / on(pod) sum(kube_pod_container_resource_limits_cpu_cores{pod=~"rewe-bd-palantir-vernemq.*", container="vernemq", job="kubernetes-pods"}) by (pod)