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]
(..) ..and that he saved me. ln every way that a person can be saved. l don't even have a picture of him. He exists now only in my memory. (Man) Keldysh, Keldysh, Mir on our way to the surface. (Brock) l was saving this for when l found the diamond. l'm sorry. Three years l've thought - (Applause) (..)1997 Titanic