Here is a UDF by Stephen Bullen that will do it

Function FilterCriteria(Rng As Range) As String
   'By Stephen Bullen
'use like =FilterCriteria(A3)
' The single-cell argument for the FilterCriteria function
' can refer to any cell within the column of interest
'do not use the cell with the arrows, it will not update

   Dim Filter As String
   Filter = ""
   On Error GoTo Finish
   With Rng.Parent.AutoFilter
       If Intersect(Rng, .Range) Is Nothing Then GoTo Finish
       With .Filters(Rng.Column - .Range.Column + 1)
           If Not .On Then GoTo Finish
           Filter = .Criteria1
           Select Case .Operator
               Case xlAnd
                   Filter = Filter & " AND " & .Criteria2
               Case xlOr
                   Filter = Filter & " OR " & .Criteria2
           End Select
       End With
   End With
Finish:
   FilterCriteria = Filter
End Function