This is an important question. Repatriating back home can be a challenging thing. In light of this, here are some suggestions.
First, companies can warn their employees who are going back to their home countries that there will be adjustment issues. In addition, they may even want to offer a course or counseling not only for the employee, but also for the employee's family. This can help very much.
Second, when these employees finally get back home, it would be helpful for a company to set up their employees with other people and their families who are in the same boat. There is a certain level of comfort knowing that others feel the same as you do.
Finally, compensation can help as well. This shows that the company appreciates the hard work overseas.