https://github.com/purcell/ibuffer-projectile.git
    git clone 'git://github.com/purcell/ibuffer-projectile.git'
      
    
  
  Emacs' ibuffer-mode is a wonderful replacement for the built-in
list-buffer command, and allows buffers to be grouped
programatically, e.g. by major mode.
ibuffer-projectile lets you group your buffers by their projectile
root directory.
You can use this package manually or automatically. For manual use,
call ibuffer-projectile-set-filter-groups. To have this function
called when you open ibuffer, add this hook to your configuration:
(add-hook 'ibuffer-hook
    (lambda ()
      (ibuffer-projectile-set-filter-groups)
      (unless (eq ibuffer-sorting-mode 'alphabetic)
        (ibuffer-do-sort-by-alphabetic))))
Alternatively, use `ibuffer-projectile-generate-filter-groups' to programmatically obtain a list of filter groups that you can combine with your own custom groups.
I personally use ibuffer-vc because I prefer its grouping behaviour, but I thought this would be useful to some people too.
Add ibuffer-projectile.el to your load-path, or (preferred) install from Melpa.