If you think she only did it for the money, you haven't even 'scratched the surface'. [=there are many other factors, reasons, etc., involved]
Despite the 'surface' differences between the two candidates, they are very similar in most ways.
The tension between them is beginning to 'rise to the surface'. [=it is becoming easy to see]
(..) No, forget it. One hundred percent! I am in! I think... Do you hear that? I do. That's Agnes calling me from on the surface. Totally in! You know what? I am not so convinced that he is in. Edith, Agnes, come on! Ooh! (..)2013 Despicable Me 2