The Multi clients feature will allow you to create multiple clients for a matter, by following the steps below:
Create your client in the system by following the standard process and then create a Matter for that client.
Within the Matter, click on the Clients Tab.
Select the client icon to the top right of the client screen.
A screen will be presented where you can add another client. Populate the relevant fields and click Save.
The new client will be added to the list. If you would like to make them the Lead client, right click on the entry and click Promote to Lead Client.