private static String cleanGroup(String group) {
        group = clean(group, NAME_JOINER);
        return GROUP_PATTERN.matcher(group).replaceAll("");
    }
This method maps a group name to follow conventions and cleans up the result to be more legible:
<ul>
 <li> converts names to lower case conventions
 <li> normalizes artifacts of hyphen case in group name to dot separated conversion
 <li> strips redundant parts of the metric name, such as -metrics
</ul>
clients/src/main/java/org/apache/kafka/common/telemetry/internals/TelemetryMetricNamingConvention.java