Is it permissible to return to a divorced wife, knowing that this will cause a rift with the family, and what is the Islamic legal position on this issue?

If the wife was divorced with a revocable divorce and is still in her waiting period (iddah), then it is permissible to take her back, and there is no obligation to obey the family in not taking her back. However, if she was divorced with an irrevocable divorce, or her waiting period (iddah) has ended, and the parents object, then their obedience takes precedence over marrying a specific woman, and it is advised to try and convince them. If the objector is not one of the parents, then there is no harm in marrying her, even if it leads to their boycotting him, while continuing to maintain ties with them and be dutiful towards them.