There is an undergraduate minor in entrepreneurship offered by the graduate school of engineering management (the most popular minor at Tufts) and all the entrepreneurship center activities.
There is the finance minor
https://as.tufts.edu/economics/current-students/undergraduate-programs/minor-finance
and the Tufts financial group
There is an international economics track within iternational relations
For marketing and advertising there are “practice” courses in marketing as well as an internship that can be taken independently or as part of the media studies minor
https://as.tufts.edu/fms/courses/practice
There is a course on career planning offered through the ExCollege and there are often business related courses taught by students or business professionals
https://excollege.tufts.edu/current
As a part of the career center there is a community for business