You should be entering all your Controls in a TableLayoutPanel. You can control how the row and column move. One catch, only one control per cell, so sometimes you have to either nest another TableLayoutPanel or dock a panel control back into a cell to get all the things you need back on screen. On the left is my form as designed, on the right my re-sized one while running in debug mode.
Deep Dive
1 TablelayoutPanel of 4 columns & 5 rows, 1 groupbox, 2 buttons
Column 0 = Fixed at 20px
Column 1 = 100%
Column 2 = Auto-Sized to Control
Column 3 = Fixed at 20px
Row 0 = Fixed at 20px
Row 1 = 100%
Row 2 = Fixed at 20px
Row 3 = Auto-Sized to Control
Row 2 = Fixed at 20px
Button1 in Column 1 at Row 3, Anchored Right
Button2 in Column 2 at Row 3, Anchored Right
Groupbox in Column 1 at Row 1, colored for visibility, dock = Fill, ColSpan = 2
TableLayoutPanel Dock=Fill