Need to connect a relational table to a separate table

Requirement is to students attend courses and each student is able to select to attend which course in which institutions. As you can see student 1 has chosen to attend courses A and B and want to attend course A in institution I1 and I2.

Student          
1         
2       
3        

Course
A
B
C

Student_Course
1         A
1         B
2         A
3         C

School
Student  Course Institution
1          A      I1
1          A      I2
1          B      I6
2          A      I5
3          C      I3

Entities

@Entity
public class Student {
   @Id
   long id;
   @ManyToMany
   List<Course> courses;
   ...
}

@Entity
public class Course {
  @Id
  long id;
}

@Entity
public class Institution {
 ?????
}