macro for selecting scenario and copying results

Do you have a sample file that you can upload?

To Attach a File:

1. Click on Go Advanced
2. In the frame Attach Files you will see the button Manage Attachments
3. Click the button.
4. A new window will open titled Manage Attachments - Excel Forum.
5. Click the Browse... button to locate your file for uploading.
6. This will open a new window File Upload.
7. Once you have located the file to upload click the Open button. This window will close.
8. You are now back in the Manage Attachments - Excel Forum window.
9. Click the Upload button and wait until the file has uploaded.
10. Close the window and then click Submit.

If there is data existing in target1, target2 and target3, it should be cleared out before fresh data is input?

Try this code. Right click on the sheet, select View code and copy paste it into the code window. Then just change the dropdown and the code will work.

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$B$9" Then
    Range("B12:B14,E12:E14,H12:H14").ClearContents
    If Target.Value = "1" Then
        Range("F5:F7").Copy
        Range("B12").PasteSpecial (xlPasteValues)
    ElseIf Target.Value = "2" Then
        Range("F5:F7").Copy
        Range("E12").PasteSpecial (xlPasteValues)
    Else
        Range("F5:F7").Copy
        Range("H12").PasteSpecial (xlPasteValues)
    End If
End If
End Sub

Try this

Option Explicit

Sub copy_range()
Dim i As Long, a As Long

a = 2
With Worksheets("Sheet1")
    For i = 2 To 8 Step 3
        .Range(.Cells(12, i), .Cells(14, i)).ClearContents
    Next i
    
    For i = 1 To 3
        .Range("B9").Value = i
        .Range("F5:F7").Copy
        .Cells(12, a).PasteSpecial (xlPasteValues)
        a = a + 3
    Next i
End With

End Sub

Put it in a standard module and then you can assign it to a button.