Build a jekyll site out of several repositories (github))

Thanks Michael.
My apologies I didnt’ explained the problem.
I have repository A (which is this one / Gh-pages) and repository B (this / Gh pages). I want this and hipotethically N repositories to be rendered on a mother repository, that collects and possibly allow the tag research among all posts in the Schede folder (the post) .

Is it now more clear?
thanks in advance