Hi Cihan,
Instead of using campaign level targeting, you could use experience level targeting , and instead of using both of the conditions I mentioned in my post earlier , you could think of using referrers as being sample.com, or sample1.com as per your requirements.
Please know that if someone directly types an answer, then that would make the referrer go blank—that is how the javascript works—and if the person comes from google, then the referrer becomes google.com, so by the targeting I just mentioned, this visitor would be left out and would not be shown this offer at all. But if you use experience level targeting, this is possible.
Please let me know if this message was useful for you.
Thanks and glad to be of help-
Avik