Hey Nina,
To piggy-back on to Charlie's point, you will need to add the filter to each campaign you run that is not the nurture. There is no way to say "if this record is part of this campaign, do not send any other emails" on a global basis. However you designate that a record is part of the nurture (program status, custom field, static/smart list membership), you will need to account for those records in each campaign you run and actively exclude them.