Set up numbers into MultiLevel tree

[Forestq]

Hi,

I need to generate number into column F, based on hierarchy (col B:D), below is excel examaple:

A	B	C	D	E	F
1
2					Looking Numbers
3	A1				1
4		A1.1			101
5		A1.2			201
6		A1.3			301
7			A1.3.1		10301
8
9	B1				2
10		B1.1			102
11		B1.2			202
12			B1.2.1		10202
13			B1.2.2		20202
14		B1.3			302
15		B1.4			402
16
17	C1				3
18		C1.1			103
19			C1.1.1		10103
20			C1.1.2		20103

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I know only how to set A1, B1 and C1 value.

ws_c = ws1.Cells(Rows.Count, "D").End(xlUp).Row
Dim Lev1, Lev2, Lev3 As Long
Lev1 = 1
    For i = 3 To ws_c
    
        If ws1.Range("B" & i).Value <> "" Then
           ws1.Range("F" & i).Value = Lev1
           Lev1 = Lev1 + 1
        End If
    Next