Moodle in English

Yes, there is.

You can use the very same suggestion that John pointed out in courses with the Choice activity but you can then use the access restrictions on it to restrict it to a particular Group in the course. You can automatically have Cohorts synchronize into course Groups by using this plugin: https://moodle.org/plugins/enrol_groupsync which is very good. So, make a Choice with the policies for Cohort A in it, restrict it to Group A, and use the plugin to create and synchronize the members of the Cohort A with the Group A automatically. Same for Cohort B, etc.

The limitation of this method is that a user may have to do it in several courses, if you add it to more than one course. Since Cohorts don't have any "space" for the group (it's an enrolment method after all), inside a course is really the only place to do this.