1. you can try this way:
2. 
   

3. Define the boolean fields:

   • "field_boolean1" on the "sale.order" model
   • "field_boolean2" on the related "res.partner" model

4. Inherit the "sale.order" model:

   • Create a new custom module or open an existing one where you want to make the changes.
   • Inherit the "sale.order" model using the appropriate Odoo/OpenERP method (e.g., models.Model or models.TransientModel).

5. Override the "partner_id" field:

   • Inside your custom module, override the "partner_id" field to modify its domain filter.
   • Set the domain based on the conditions you specified:
     • If "field_boolean1" is true, show only the records in "partner_id" where "field_boolean2" is also true.
     • Otherwise, show all records in "partner_id".

example:

from odoo import models, fields

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

partner_id = fields.Many2one(
domain="[('field_boolean2', '=', True)]",
compute='_compute_partner_id',
store=True
)

@api.depends('field_boolean1', 'partner_id')
def _compute_partner_id(self):
for order in self:
if order.field_boolean1:
order.partner_id = order.partner_id.filtered(lambda r: r.field_boolean2)
else:
order.partner_id = order.partner_id

1. Update your module:
   • Make sure to update your module dependencies and other required files (e.g., __manifest__.py) accordingly.
   • Restart the Odoo server to load the changes.

Hi,

Seems you need to apply domain for the partner_id field in the sale.order model based on a field in the same model. Here you have two approaches, either you can return domain from an onchange function, which is deprecated in the latest version and not a stable method. Then using the web_domain_field module and using a computed field, it can be achieved.

See this video explaining the same:   https://www.youtube.com/watch?v=dq5Vtj_pwuI&t=311s

Thanks