Allow fzf action to change directory

- Category
- Question
- Suggestion
- OS
- macOS
- Vim
- Neovim

For me to explain properly, I should preface with relating these things;
- "root" directory? (simply `/` or something similar) (**root**)
- current vim directory (**current**)
- active buffer directory (**active**)

During a fzf search, we can order these (relative to each other on the absolute path) using scope as a metric like so.
`root` >= `current` >= `active`
for example;

#### **root**`/path/to/`**current**`/and/to/`**active**

Notice how `fzf` does a search (by default anyways) from **current** onwards. But suppose I want to widen or narrow down my scope of search _during the search_. Is this possible? That is to move my vim directory left or right? (in reference to my diagram)

You know - like add a fzf action that'd mapped something like `ctrl-h` to `cd ..` and ctrl-l to `cd ..` and `cd and`?

Is this already possible? If not, is this a good idea? I would totally be keen to give this a crack over the month or so if you find this is a good idea.

Thanks heaps.