You can transfer an active WhatsApp chat to another user or to a WhatsApp group. The user or the group that receives the chat continues the conversation with the WhatsApp contact.
Prerequisites
WhatsApp messaging is enabled for your account.
The WhatsApp chat has an active session. For more information, see Sending a Message.
Transferring a WhatsApp Chat
To transfer a WhatsApp chat:
Open the WhatsApp chat that you want to transfer.
At the top of the chat window, select the ellipsis icon, and then select Transfer session.

From the list, select the user or the group that you want to transfer the chat to. The list displays only WhatsApp groups and users who have WhatsApp messaging enabled. The WhatsApp contact does not appear in the list.
In the confirmation message, select Transfer. If you transfer the chat to a group, the confirmation message displays Transfer chat from private conversation to <group name>?

After the transfer completes, the message Chat transferred to <user name> appears, where <user name> is the name of the user who receives the chat.
Note
When another user transfers a WhatsApp chat to you, the message <user name> transferred this chat to you appears.