Что будет делать:
Sub test()
Dim MyPath As String, mps As Variant, mps_temp As String, mydate As Date, i As Integer
MyPath = "G:\Inbox\Folder1\Received\2019 03 01\2019 03 02\2019 03 05\Final"
mps = Split(MyPath, "\")
For i = LBound(mps) To UBound(mps)
mps_temp = mps(UBound(mps) - i)
If mps_temp Like "#### ## ##" Then
mydate = DateSerial(Mid(mps_temp, 1, 4), Mid(mps_temp, 6, 2), Mid(mps_temp, 9, 2))
Exit For
End If
Next
msgbox mydate
End Sub