Yes, it is possible to migrate specific chats instead of the entire chats of the users.

To achieve this, perform the below steps.

Step 1 : Navigate to Chat -> Source -> Users. Select the users whose specific chats you wish to migrate. Click ‘Sync Chats’

Note : After syncing, a “Sync Chat” task will be created. Once it’s completed, users can view the chats under the Chat tab.

Step 2 : Navigate to Chat -> Source -> Chats. Here the entire chats of the selected users are listed. Select the specific chats you wish to migrate. Click ‘Migrate’