Revert "refactor(#2871, #2886): multi instance: node classes created (#2916)"

This reverts commit 38aac09151.

lua/nvim-tree/actions/fs/create-file.lua

@@ -1,5 +1,6 @@
 local utils = require("nvim-tree.utils")
 local events = require("nvim-tree.events")
+local lib = require("nvim-tree.lib")
 local core = require("nvim-tree.core")
 local notify = require("nvim-tree.notify")
 
@@ -39,13 +40,14 @@ local function get_containing_folder(node)
   return node.absolute_path:sub(0, -node_name_size - 1)
 end
 
----@param node Node?
+---@param node Node|nil
 function M.fn(node)
   local cwd = core.get_cwd()
   if cwd == nil then
     return
   end
 
+  node = node and lib.get_last_group_node(node)
   if not node or node.name == ".." then
     node = {
       absolute_path = cwd,
@@ -53,8 +55,6 @@ function M.fn(node)
       nodes = core.get_explorer().nodes,
       open = true,
     }
-  else
-    node = node:last_group_node()
   end
 
   local containing_folder = get_containing_folder(node)