Looking for a little exposition on a new "Add paginator support for page groups"

Continuing the discussion from Pagination and group by date:

My original query was the goal to have a paginator such that it would group a month’s worth of postings together at a time. It looks like @bep added this, but it’s been a year since I’ve looked at it and there has been a new release and I’m hoping to get pointed to a theme that does things this way. Thanks!