Parent - Child Hierarchy

[Kingsley MG]

Data as below
[TABLE="width: 128"]
<tbody>[TR]
[TD="class: xl63"]Parent[/TD]
[TD="class: xl63, width: 64"]Child[/TD]
[/TR]
[TR]
[TD="class: xl63"]AAA[/TD]
[TD="class: xl63"]BBB[/TD]
[/TR]
[TR]
[TD="class: xl63"]BBB[/TD]
[TD="class: xl63"]CCC[/TD]
[/TR]
[TR]
[TD="class: xl63"]AAA[/TD]
[TD="class: xl63"]DDD[/TD]
[/TR]
[TR]
[TD="class: xl63"]DDD[/TD]
[TD="class: xl63"]EEE[/TD]
[/TR]
[TR]
[TD="class: xl63"]EEE[/TD]
[TD="class: xl63"]FFF[/TD]
[/TR]
[TR]
[TD="class: xl63"]CCC[/TD]
[TD="class: xl63"]GGG[/TD]
[/TR]
[TR]
[TD="class: xl63"]GGG[/TD]
[TD="class: xl63"]HHH[/TD]
[/TR]
[TR]
[TD="class: xl63"]HHH[/TD]
[TD="class: xl63"]III[/TD]
[/TR]
[TR]
[TD="class: xl63"]III[/TD]
[TD="class: xl63"]JJJ[/TD]
[/TR]
[TR]
[TD="class: xl63"]III[/TD]
[TD="class: xl63"]KKK[/TD]
[/TR]
[TR]
[TD="class: xl63"]JJJ[/TD]
[TD="class: xl63"]LLL[/TD]
[/TR]
[TR]
[TD="class: xl63"]KKK[/TD]
[TD="class: xl63"]MMM[/TD]
[/TR]
[TR]
[TD="class: xl63"]MMM[/TD]
[TD="class: xl63"]NNN[/TD]
[/TR]
</tbody>[/TABLE]
and continues.

Output should be collapsed. EX. as below
[TABLE="width: 297"]
<tbody>[TR]
[TD]AAA[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]+[/TD]
[TD]BBB[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD]+[/TD]
[TD]CCC[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]GGG[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]HHH[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]III[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]JJJ[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]LLL[/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]KKK[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]MMM[/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]NNN[/TD]
[/TR]
[TR]
[TD]+[/TD]
[TD]DDD[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD]+[/TD]
[TD]EEE[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[TD]+[/TD]
[TD]FFF[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
</tbody>[/TABLE]
and continue as per the Parent - Child data.

 

[Fazza]

hello. suggest you test it on further data, & modify as required if you find errors/deficiencies. cheers

Sub maybe()    
    'https://www.mrexcel.com/forum/excel-questions/1066730-parent-child-hierarchy.html
    
    'CODING ASSUMES input data is on worksheet called "input data" & results go to worksheet "output"
    
    Dim i As Long
    Dim lColumn As Long
    Dim sThisChild As String
    Dim sThisParent As String
    Dim rng As Excel.Range
    Dim ar As Variant
    
    ar = Worksheets("input data").Range("A1").CurrentRegion.Value2


    With Worksheets("output")
        .Cells.Clear
        'start with first data and populate worksheet..
        'Put first data in worksheet, from row 2 of input data
        .Cells(1, 1).Value2 = ar(2, 1)
        .Cells(2, 1).Value2 = "+"
        .Cells(2, 2).Value2 = ar(2, 2)
        
        'Now loop through all others
        For i = LBound(ar, 1) + 2 To UBound(ar, 1)
            sThisParent = ar(i, 1)
            sThisChild = ar(i, 2)
            
            'check if the parent is already in the worksheet
            Set rng = .Cells.Find(What:=sThisParent, LookAt:=xlWhole)
            
            If rng Is Nothing Then
                'Parent data is not yet on the worksheet.
                'This new data can be posted to the worksheet's first row or become the new last row.
                'Make it the last row for consistency with image posted in question.
                'Work out the current last row,
                Set rng = .Cells.Find(What:="*", After:=.Range("A1"), SearchOrder:=xlByRows, SearchDirection:=xlPrevious)
                .Cells(rng.Row + 1, 1) = sThisParent
                .Cells(rng.Row + 2, 1).Value2 = "+"
                .Cells(rng.Row + 2, 2) = sThisChild
            Else
                'Parent data is already on the worksheet. So add this data as a child to it.
                'if there is not yet a child,
                If Len(rng.Offset(1, 1).Value2) = 0 Then
                    rng.Offset(1).EntireRow.Insert
                    rng.Offset(1).Value2 = "+"
                    rng.Offset(1, 1).Value2 = sThisChild
                Else
                    'find end of this branch
                    lColumn = rng.Column
                    Do
                        Set rng = rng.Offset(1, 1)
                    Loop Until Len(rng.Offset(1, 1).Value2) = 0
                    rng.Offset(1).EntireRow.Insert
                    .Cells(rng.Row + 1, lColumn).Value2 = "+"
                    .Cells(rng.Row + 1, lColumn + 1).Value2 = sThisChild
                End If
            End If
            
        Next i
    End With


End Sub