It could look something like this. The middle of the brackets could look like this or flip flopped.
top or bottom of bracket
D1-1st
D2-4th
D3-3rd
D4-2nd
D3-2nd
D4-3rd
D1-4th
D2-1st
top or bottom of bracket
D3-1st
D4-4th
D1-3rd
D2-2nd
D1-2nd
D2-3rd
D3-1st
D4-4th