how to enable mTLS for multiple clients on same broker

[redoc123]

As per documentation, you can configure only a single client certificate in broker.conf

#configure mTLS for the internal client
brokerClientTlsEnabled=true
brokerClientTrustCertsFilePath=/path/to/ca.cert.pem
brokerClientCertificateFilePath=/path/to/client.cert.pem
brokerClientKeyFilePath=/path/to/client.key-pk8.pem

Consider a scenario where I have two different applications from two different business units connecting to a broker.

How do I enable mTLS between both the applications and broker without sharing client side cert key pair??