Need to find matching data in filtered columns

Probably missing something obvious here.

Code needs to filter Col C to show only entries with "2" value (which means there are two records with the same combination in Col B).

What I cannot see is how to then "find" each pair in Col B? Because if I don't know what row number will be the first filtered record, I won't be able to set the "Find" function to look for whatever is in Col B of that row, then cycle to the next visible row.

Having found the pair, the Code will then compare Col A. If both values match, the records go to Col H - J, and if they are different the records go to Col M, as shown on the attached.

Option Explicit

Dim a As Integer
Dim rng As Range


Sub SETPAIRS()

    With ActiveSheet
    a = .Cells(.Rows.Count, "A").End(xlUp).Row
    End With

'Select rows where Column C is 2:

    ActiveSheet.Range("A1:C" & a).AutoFilter Field:=3, Criteria1:="2"

'Find "pairs" in Col B: 

'Loop through Column B, looking for matching values
   
    Set rng = Range("B2", Range("B").End(xlDown)).Cells.SpecialCells(xlCellTypeVisible)
    Const WHAT_TO_FIND As String = "??" 'How do I know the first filtered row number, or what it will say in Col B?

'First thoughts on how to then check whether Col A is identical where a pair is found (Code incomplete) 
          Set m = ws.Range("B:B").Find(What:=WHAT_TO_FIND) 'This will be whatever is in Col B of the first filtered row
           If Not m Is Nothing Then
            For Each cell In rng
           Set m = .Find(Range("A" & rw))
           If m Is Nothing Then
          Next

    End Sub

All suggestions, pointers and solutions accepted gratefully, as ever

Ochimus

Maybe this will work for you

Sub FindPairs()
 Dim arr, tmp, i As Long
 Dim key

 With ActiveSheet
    arr = .Range("a1").CurrentRegion
 End With
 
 With CreateObject("scripting.dictionary")
    For i = 1 To UBound(arr)
        If arr(i, 3) = 2 Then
            key = arr(i, 1) & arr(i, 2) & arr(i, 3)
            If Not .exists(key) Then
                tmp = Array(arr(i, 1), arr(i, 2), arr(i, 3), 1)
            Else
                tmp = .Item(key)
                tmp(3) = tmp(3) + 1
            End If
            .Item(key) = tmp
        End If
    Next
    For Each key In .keys
        If .Item(key)(3) > 1 Then
            ActiveSheet.Cells(Rows.Count, "H").End(xlUp).Offset(1).Resize(.Item(key)(3), 3) = .Item(key)
        Else
            ActiveSheet.Cells(Rows.Count, "M").End(xlUp).Offset(1).Resize(, 3) = .Item(key)
        End If
    Next
 End With
End Sub