Go to “Campaign”, click on “New Campaign”.
Fill the initial entries and click on “Launch Campaign Builder”.
Create the campaign and the decision as OPEN inside it accordingly.
Now you can create the “Action” under the given decision, click on “Select”.
Select “Modify Contact Segments”.
Choose all the required entries in the given window and click on “ADD” button, and now by doing this, all the contact will move into a new segment if they open an email.