Points. Accesibility Test Help ¡¡¡

For my PhD thesis I´m making a connectivity / accesibility test of a certain urban area streets.

i have a problem with the accesibility test, cause i need to know wich points of the grids have direct connections with the others, as the image example

Any idea, to how finally get a list with all the points and their direct accesibility correspondence?????

Thanks ¡¡¡¡¡¡¡¡¡¡¡

Ps: here are the 3dm & Gh files

PhD_Connectivity_Test.3dm

PhD_Connectivity_Test.gh