Octahedron 3d pattern

Hi! i'm trying to realize a 3d octahedron pattern and i'm encountering some difficoluties with the data managing.

basically i have to connect the point of the grid in a specific order to create the correct line and obtain the octahedron..

i tried with a lot with data trees managing and list but i did't figured out how to do that in the best way

does anyone has any suggestion?