find common cells among multiple columns in excel

Option Explicit
Public Sub get_common_value_from_multiple_columns()

    'Dim data_dictionary As New Scripting.Dictionary
    Dim data_dictionary As Object
    Set data_dictionary = CreateObject("Scripting.Dictionary")
    
    Dim columns_count As Long
    Dim iterator As Integer
    Dim dictionary_item As Variant
    Dim selected_cells As Variant
    
    Set selected_cells = Cells(1, 1).CurrentRegion
    columns_count = selected_cells.Columns.Count
    selected_cells.Select
    
    'Populate the dictionary defined earlier
    For iterator = 0 To columns_count - 1:
        For Each dictionary_item In selected_cells.Columns(iterator + 1).Value
            If Not data_dictionary.Exists(dictionary_item) Then
                data_dictionary.Item(dictionary_item) = 1
            ElseIf data_dictionary.Exists(dictionary_item) Then
                data_dictionary.Item(dictionary_item) = data_dictionary.Item(dictionary_item) + 1
            End If
        Next dictionary_item
    Next iterator
    
    'Remove the unique values
    For Each dictionary_item In data_dictionary
        If data_dictionary.Item(dictionary_item) < iterator Then
            data_dictionary.Remove dictionary_item
        End If
    Next dictionary_item
    
    'Copy the common value to a new columns
    If data_dictionary.Count > 0 Then
        Cells(columns_count + 2).Resize(data_dictionary.Count) = Application.Transpose(data_dictionary.Keys)
    End If
    
End Sub