No. Each new user can only be linked to one referrer — whoever's link or code they used when they signed up. Once an account is created, the referral can't be reassigned or split.
If you think a friend meant to use your link but signed up with someone else's, unfortunately we can't change it after the fact. The best way to make sure you get credit is to have them sign up directly from your link, or enter your code during registration.