What is the ruling of Islamic law regarding a group of worshippers withdrawing from the Eid prayer due to their disagreement with the Imam, and what are the implications of this, such as harming Muslims in the country?

It has been previously explained that the ruling on the Eid prayer is that it is permissible to perform it in congregation or individually. According to the view that it is obligatory or a Sunnah (which is the more preponderant opinion), it is not permissible to interrupt it after commencing it. If "leaving" means leaving before the prayer without a valid Shar'i excuse, then they have acted wrongly and caused disunity.