Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
Dim x As Range
If Target.Address = "$C$5" Then
Set x = Range("A8", Range("A65536").End(xlUp)).Find(Target, , xlValues, xlWhole, , , False)
If Not x Is Nothing Then x.EntireRow.Hidden = Target.Row = 5
End If
If Target.Address = "$C$3" Then
Set x = Range("A8", Range("A65536").End(xlUp))
With Application
If Not IsError(.Match(Target, x, 0)) Then Rows(.Match(Target, x, 0) + 7).Hidden = False
End With
End If
End Sub