Here's what I'd like to do, and I'm open to using any tool (not just fzf):
I want to be able to open a new file quickly (with a horizontal split :sp) in a specific directory that I find using fzf. Say we're working with this structure
foo/ bar/ file.js poop/
While I have file.js open in my buffer, I should be able to fuzzy find the foo/poop/ directory and open a new file foo/poop/newfile.js in a split window.