Last summer we had Maharashtra team visiting Bangladesh to play T20s against national team, one-day and four day matches against A-team. Maharashtra also hosted our A-team later in the summer for a tour.
SL academy also came for a tour last summer (quite a few players from that team have been later selected for Lanka senior team). Later in the summer BCB academy went on a tour of South Africa.
If you want to look at tours and leagues taking place on Bangladesh, cricket archive is the best site to look at -
BCB can always do better, but it's not like they are doing nothing. At least, our board don't deserve to be compared with ZC.