Dim strSQL as String
strSQL = "SELECT * FROM YourTableNameHere WHERE YourFieldNameHere=" & Forms!YourMainFormNameHere.ControlNameHere
Forms!YourMainFormNameHere.Form.YourSubFormContainerNameHere.Recordsource = strSQL
Forms!YourMainFormNameHere.Form.YourSubFormContainerNameHere.Requery