Not sure if there is something more up to date...
http://www.ncaa.com/news/basketball-men/article/2013-08-01/committee-changes-bracketing-guidelines-division-i-tournament"This means that teams from the same conference that played only once during the season can now face each other as early as the third round of the championship. Subsequently, teams from the same league that met twice during the year will not potentially play each other until the regional semifinals. Also, teams from the same league that played each other three times during the course of the season cannot play until the regional championship game.
The previous guidelines did not allow more than two teams from a league to be in the same region unless nine or more teams were selected from one conference. This has only occurred twice in the history of the championship (Big East with 11 teams in 2011 and nine in 2012). Under the new principles, each of the top four teams selected from a conference will be placed in separate regions, only if they are seeded on the first four lines. This replaces the principle that separated the top three teams from a league regardless of the teams’ placement within the bracket."