Get rid of site-wide forum categories in drop down menu

I would love if all site-wide forums (forums from all groups) were not displayed when a user submits a forum post within a group. I believe only the group forum (or mulitple group forums if this were possible) should be displayed (or not at all if multiple forums are not possible). Because if you have hundreds of groups within your site, when the user goes to submit a forum post they will have to weed through hundreds of forums in the drop down menu in order to find the correct one. This is not good.

Going along with this, forum posts within a group should be group sensitive. If a user posts a fourm topic within group X, the post should automatically get posted within group X (or the user should have a choice of forums within group X (if this were possible)) and not site-wide. I hope this makes sense because it's very important if you have many groups within your website. Can this be a feature? Is any of this possible right now?