Count Rows Until Cell Value or Cell Value Changes

Sub CountRows()
    Application.ScreenUpdating = False
    Dim LastRow As Long
    LastRow = Cells.Find("*", SearchOrder:=xlByRows, SearchDirection:=xlPrevious).Row
    Range("B1:B" & LastRow).AdvancedFilter Action:=xlFilterInPlace, CriteriaRange:=Range _
        ("B1:B" & LastRow), Unique:=True
    Set rngUniques = Range("B2:B" & LastRow).SpecialCells(xlCellTypeVisible)
    If ActiveSheet.FilterMode Then ActiveSheet.ShowAllData
    Dim fRow As Long
    Dim lRow As Long
    Dim strFirst As Range, strLast As Range
    Dim rng As Range
    Dim counter As Long
    For Each rng In rngUniques
        Set strFirst = Range("B2:B" & LastRow).Find(What:=rng, _
                            LookAt:=xlPart, _
                            SearchOrder:=xlByRows, _
                            SearchDirection:=xlNext, _
                            MatchCase:=False)
        If Not strFirst Is Nothing Then
            fRow = strFirst.Row
            Set strLast = Range("B2:B" & LastRow).Find(What:=strFirst, _
                                LookAt:=xlPart, _
                                SearchOrder:=xlByRows, _
                                SearchDirection:=xlPrevious, _
                                MatchCase:=False)
            If Not strLast Is Nothing Then
                lRow = strLast.Row
            End If
        End If
        counter = Application.WorksheetFunction.CountIf(Range(Cells(fRow, "A"), Cells(lRow, "A")), "3")
        MsgBox ("L2Item Group " & rng & " - " & counter & " rows of Level 3 Items")
    Next rng
    Application.ScreenUpdating = True
End Sub

Sub SortAssemblyTable()

    Application.ScreenUpdating = False
    
'Range will be variable later
    Dim rng As Range
        Set rng = Range("B6:M25")
    
    Dim rw As Range
    Dim cll As Range
    Dim Level3Count As Long
    
    For Each rw In rng.Rows
        For Each cll In rw.Columns


            If cll.Column = rng.Columns(1).Column And cll.Value = 3 Then
               
                Level3Count = 1
                Do Until cll.Column = rng.Columns(1).Column And cll.Value = 2
                    
'Enter some code here for rows.count or countif?


                Loop
                
                'Apply other code based on number of level 3 rows.
                
            End If


        Next cll
    Next rw
End Sub

Range("B1:B" & lastRow).AdvancedFilter Action:=xlFilterInPlace, CriteriaRange:=Range _        ("B1:B" & lastRow), Unique:=True
    Set rngUniques = Range("B2:B" & lastRow).SpecialCells(xlCellTypeVisible)
    If ActiveSheet.FilterMode Then ActiveSheet.ShowAllData