Hi, 

You can follow following link for this:

https://youtu.be/GPhgxxwprA4

Hope it helps,

Thanks

use like this

field_name = fields.Selection(selection=lambda self: self.dynamic_selection(), string="Scheme", tracking=True)

def dynamic_selection(self):
        objs = self.env['object.name'].sudo().search([])
        selection = [(rec.scheme, rec.scheme) for rec in objs]
        return selection