Your business layer should operate on top of your data layer and be organized into logically connected groups. Something like this:
public class EmployeeInfoOperations {
public final void updateName(Employee employee, String newName) {
//bussines logic: trigger name update on external systems?
}
public final void updateContactAddress(Employee employee, Address newAddress) {
}
}
public class EmployeeAccounting {
public final void changeSalary(Employee employee,float newSalary) {
}
public final void giveBonus(Employee employee, bigdecimal bonusAmount) {
}
}
Your bussiness operation classes don't even have to be centric around one entity type. Think about group of business operations, small enough to become one class, and use any entity types as arguments.