fix(#2154): find_file doesn't work when group_empty option is enabled (#2100)

Co-authored-by: Alexander Courtis <alex@courtis.org>

lua/nvim-tree/actions/tree-modifiers/expand-all.lua

@@ -2,6 +2,7 @@ local core = require "nvim-tree.core"
 local renderer = require "nvim-tree.renderer"
 local Iterator = require "nvim-tree.iterators.node-iterator"
 local notify = require "nvim-tree.notify"
+local lib = require "nvim-tree.lib"
 
 local M = {}
 
@@ -15,6 +16,7 @@ local function to_lookup_table(list)
 end
 
 local function expand(node)
+  node = lib.get_last_group_node(node)
   node.open = true
   if #node.nodes == 0 then
     core.get_explorer():expand(node)
@@ -45,7 +47,8 @@ local function gen_iterator()
         end
       end)
       :recursor(function(node)
-        return expansion_count < M.MAX_FOLDER_DISCOVERY and node.open and node.nodes
+        return expansion_count < M.MAX_FOLDER_DISCOVERY
+          and (node.group_next and { node.group_next } or (node.open and node.nodes))
       end)
       :iterate()