Could you please give more details about your questions?
If you create the two panels in the designer, just simply move and resize the child panel to make it inside the parent panel.
If you create the two panels programmatically, you can set the bounds of the child panel by setting
Panel.Bounds Property or by calling
Panel .SetBounds Method.
If you still have any doubt and concern about this issue, please let us know. If I misunderstood you, please kindly elaborate your question.