Hello,
Monitoring consumer group lag using Cloudera Manager seems unlikely as I tried configuring a chart to display the consumer group lag but couldn't generate the desired results.
However, on further research, I came around a few GitHub projects that provide additional monitoring functionality. One among them is "Kafka Manager(Yahoo, Apache 2.0 License)", I think with this tool you can monitor consumer group lag.

Please refer mentioned link[1] for more information on Kafka Manager.
[1]https://github.com/yahoo/kafka-manager