Attaching a relationship contact is as easy as 1,2,3!
Just search for the name of the contact to whom you want to add a relationship then click the + sign below the Contact Details screen located on the left panel. Alternatively, you can also scroll down to the Relationship field and click the double-dash icon.
You will then be directed to the relationship info page. There, you will search for the contact (if it exists on your database) or add the details for the new contact. Select the relationship type and other necessary details then Save.
And that's it!
If you'd like to remove a contact relationship, please read this article to learn how.