How can I export all of the packets that are displayed under the conversations selection?

edit

For a specific dataset, there is a flow csv that contains 133k rows. for the corresponding pcap file, there are packets that are the ones in the csv file but the packets are displayed under the conversations selection. How can I export all of the packets that are under the conversations (TCP) selection into a newer pcap file. Thanks.

Basically how can I export all TCP conversations into another pcap?