This is more of question and I think I know why this happens but just wanted to confirm this and possibly improve on it.
I've been using YouCompleteMe for sometime and just switched to deoplete couple of weeks ago and I noticed that when I try typing the path(../) deoplete displays the path that's relative to pwd when I expected it to display files/dirs from the current file's path. The pwd path might not be the same to file path if you had opened the file with fzf or nerdtree plugin.
YouCompleteMe handles this well and uses the filepath rather than pwd path.
Is it possible to have it something like YouCompleteMe because often times when I'm working on file I sort of expect it to display relative to the file path.
" Your minimal init.vim
function! Do(info)
UpdateRemotePlugins
endfunction
Plug 'Shougo/deoplete.nvim', { 'do': function('Do') }
...
let g:deoplete#enable_at_startup = 1
inoremap <expr><TAB> pumvisible() ? "\<C-n>" : "\<TAB>"

The above screenshot is of YouCompleteMe listing files/dirs from current filepath.

The above screenshot is of deoplete listing files/dirs from pwd path.
let g:deoplete#file#enable_buffer_path = 1 is what you want.
Did not knew it was that simple. Thank you. 馃帀
Most helpful comment
let g:deoplete#file#enable_buffer_path = 1is what you want.