These details can be viewed under the support hub of a particular case. In support hub on the left bottom corner displays the Total client wait time and Total agent wait time of that case.
Total client wait time is the time period which the customer has been waiting for the agent to get back after every incoming response.
Total agent wait time is the time period an agent waits for the response from the customer after the outgoing responses.
This is calculated by total wait time in between the responses.