Below code doesn't Work:

py:

is_other_attachment = fields.Boolean(string='Other Attachment',default=False)​

other_attachment = fields.Many2many(comodel_name="ir.attachment",
                                                relation="m2m_ir_attachment_rel",
                                                column1="m2m_id",
                                                column2="attachment_id",
                                                string="Other Attachment")

xml:

<field name="is_other_attachment"/>
<field name="other_attachment" widget="many2many_binary" attrs="{'required':[('is_other_attachment', '=', True)]}"/>