BuddyPress.org

There is this plugin:
https://buddypress.org/community/groups/bp-tinymce/

And this one:
http://bp-dev.org/projects/#tinymce

Problem is both seem to have had their developers stop supporting them… Maybe somebody here can pick up the development or you can maybe find a developer to build upon them for you… You can those two out and see if they work.. I haven’t tried either.

I don’t know of any other plugins that do what you want, perhaps someone else here will…