Hi,

By using record rules, you can restrict the stock access.

1- Enable developer mode.

2- Navigate to Settings → Technical → Record Rules.

3- Configure the new Rule:

             Name: e.g., "Restrict Stock by Branch"

              Model: Select stock.quant (or the relevant model you wish to restrict).

              Domain Filter: Set a domain that filters records based on the user's assigned warehouse.

              Groups: Assign the rule to the appropriate user groups.

In the domain, you need to add the condition. 

your_branch_field:-  Refers to the branch field defined in the model (eg: stock.quant)

user.branch_field:- Refers to the branch assigned to the user.

You can also set access rights and user groups for this rule.

For more information, refer to the following: https://www.cybrosys.com/blog/how-to-create-record-rules-in-odoo-18

Hope it helps