There is a problem with one of these (or both) calls:
(the 'this' is probably unnecessary but can't be sure. i'd be curious to see why you think it's necessary.)
You didn't tell us which line (or both) was causing the error. This error:
cannot find symbol - method backUpTo(java.lang.String)
means "there's no such method called "backUpTo()" that takes a String as a parameter" (within the same 'scope' or within visibility of the calls).
Recommendation: Fix it.
If you still don't know how, then post the entire class that includes the method backUpTo().