Nesting Rows and Columns

Question

I have a hierarchical but row based spreadsheet file that looks like this when imported :

stuff = {{"Level1a", , , }
, {"Level1a", "Level2a", ,}
, {"Level1a", "Level2a", "Level3a",}
, {"Level1a", "Level2a", "Level3b",}
,  {"Level1a", "Level2a", "Level3b", "Level4a"}
, {"Level1a", "Level2a", "Level3b", "Level4b"}
, {"Level1b", , , }
, {"Level1b", "Level2b", "Level3c",}
, {"Level1b", "Level2b", "Level3d",}} // TableForm

I would like to arrange it into rows and columns like below except for some reason the align top doesn't work :

Row[{"Level1a", 
Column[{"Level2a", Column[{" Level3a", " Level3b"}], "Level2b"}], 
" Level1b", Column[{"Level2c", "Level2d"}]}, 
Alignment -> {Top, Top}]

(* Actual result wanted :
   Level1a      Level1b
     Level2a      Level2c
        Level3a      Level3c
        Level3b
     Level2b    *)

My objective is 2 fold : 1. Reformat the data.

This is how far I have got on the reformatting - I can get Parent-Child pairs :

DeleteDuplicates[Flatten[Partition[stuff, {1, 2}, 1], 2]]

(* result {{"Level1a", Null}, {Null, Null}, {"Level1a", "Level2a"}, {"Level2a", 
Null}, {"Level2a", "Level3a"}, {"Level3a", Null}, {"Level2a", 
"Level3b"}, {"Level3b", Null}, {"Level3b", "Level4a"}, {"Level3b", 
"Level4b"}, {"Level1b", Null}, {"Level1b", "Level2b"}, {"Level2b", 
"Level3c"}, {"Level3c", Null}, {"Level2b", "Level3d"}, {"Level3d", 
Null}} *)

2. Introduce Grid/Column/Row as appropriate to create the structure I want. I have already tried Map-ping but can't find a way to get them in the right place.

Answer 1

Is it possible to change structure and use a Grid instead? For example, the below gives you what you want (and it continues to make use of spaces for indentation, which you did in your example attempt).

Grid[
  {
    {
      "Level1a",
      "Level1b"
    },

    {
      " Level2a",
      " Level2c"
    },

    {
      Column[{"  Level3a","  Level3b"}],
      "  Level3c"
    },

    {" Level2b"}
  },
  Alignment->{Left,Top}
]