Hmm. At risk of misinterpreting what you're looking for - I usually just type ~ to go to my home directory, press → to browse into it, then type a couple of characters to narrow down, then just → and repeat to get somewhere. If it's a hidden or dotfolder, pressing ⌥⇧→ instead of → to show hidden files as you descent your file system. (It also seems you can use / to move to the root of the file system, instead of ~).
Alternately, to jump to a recent or open Finder window, I type 'Finder' then right-arrow to list open and recent finder windows (same way you can launch recent documents in applications).
There's nothing I've seen that autocompletes typing in full paths, though (he says, before he goes off to explore x-launchbar:select?file=*)