In TIBCO BusinessEvents, you can specify Kafka properties for broker configurations as BE properties. Add the prefix be.channel.kafka to Kafka properties to let BE identify them as Kafka channel properties. 

For example, to specify the “default.replication.factor” Kafka property, use be.channel.kafka.default.replication.factor. You can also override an existing Kafka property, which has been exposed through the BusinessEvents Studio channel editor, by using the same prefix. You can specify the property in CDD at cluster level with prefix "be.channel.kafka"

A more granular control on properties can be achieved using a modified form of the prefix. You can do so by including the channel uri in your prefix. 

Below are the sample properties that can be used in CDD.

Even more fine control is possible, you can include a destination uri in place of channel uri if you wish to set a property only for a particular destination. 

Note:
This format also follows precedence as - the finer level properties (destination level) if defined takes precedence over the broader level (channel or global) properties.