Hello, 

I am looking for a way to set a dynamic filter on the order lines in a tree view,  so that the lines are filtered depending on a field on the parent order. I tried to work with dynamic domains, but when I do that I get a warning in the console:

odoo.models: onchange method SaleOrder.onchange_active_so_section returned a domain, this is deprecated

Also the list isn't filtered, all the lines stay visible. What is the correct way to do this in odoo14?

Here is my code:

class SaleOrder(models.Model):
    _inherit = 'sale.order'

    """ FIELDS """
    active_so_section_id = fields.Many2one('sale.so_section', string="Active Section")
    
  @api.onchange('active_so_section_id')
def onchange_active_so_section(self):
    domain = {'domain': {'order_line': [('id', '=',                                     self.active_so_section_id.order_line_id.id)]}}

    return domain
The domain I get from this onchange function is like: 
 {'domain': {'order_line': [('id', '=', 67)]}}