2 sites 1 wordpress

Hey everyone,

is it possible to have 1 installation of wordpress but have a main site and a sub site reference thats wordpress?

but to complicate things, could the subsite only see certain posts, and if searching only find the posts that should be seen with the certain criteria…

e.g. A main site, B subsite, everything else random categories
post 1 Cat A, B, C, D, E, F (searchable and viewable in both main and subsite)
post 2 Cat B, C, D, E, F (searchable and viewable only in subsite)
post 3 Cat A, C, D, E, F (searchable and viewable only in mainsite)

is this possible?

if so how?