If I understand you, you want to do the same design but reversed and a different one in the middle? For ME to get them 'identical". I'd do the first row; to get the mirror image exact, make sure of your settings; length and width then get out of that design and then go back in; reverse image it then set the length and width like the first one; then they should be identical but reversed then sew your separate one down the center. You might want to do a short sample to check the distance between the two that are mirror imaged. Good luck.