Two things. First, your question: according to XPath, that would be 'gutbook//title' - this will match any 'title' element that is a child of a 'gutbook' to any depth.

Second, I don't think '$epath' is doing what you think it's doing. This is a good reason to never quote variables unless you need to. The single quotes do not do interpolation, so that you end up literally with the characters '$', 'e', 'p', 'a', 't', and 'h' making up the string. Just remove the quotes and it'll do what you want.