Hi,

If i had to do it, i would do what you suggest :

- create a simple year model that contains 1 Integer field year

- populate it with relevant range, e.g. with a csv file or with xml data

- add a many2one field to year_id in your model

- then add a dynamic domain on the Many2one field set with a 'onchange' depending of the employee_id e.g :

@api.onchange('employee_id')
def _onchange_employee_id(self):
    if self.employee_id:
        your_domain = []
        contract_year = ... get contract year from employee
        your_domain += [('year','>', contract_year)] ... or whatever you need
        domain = {'year_id': [
            your_domain
        ]}
    
        return {'domain': domain}