Hello el mehdi,

First You can add field in res.company using _inherit

You can inherit the hr.employee model and add boolean field which is related to company.

Ex:-

class Company(models.Model):
     _inherit = 'res.company'

     boolean_field_com = fields.Boolean('Boolean String Company')

class Employees(models.Model):

     _inherit = 'hr.employee'

     boolean_field_emp = fields.Boolean('Boolean String Employee', related='company_id.boolean_field_com')

Hope it works for you.

Thanks,