You can restrict internal transfers between warehouses by creating a new Operation Type in Odoo you can follow these steps:

Go to the Inventory module and select the menu "Configuration -> Settings".
Scroll down to the "Traceability" section and enable the "Manage multiple locations and warehouses" option.
Go to the menu "Inventory -> Configuration -> Warehouses" and select the warehouse that you want to restrict.
In the "Routes" tab, deselect the "Internal Transfers" route and save the changes.

With these steps, the internal transfers from the selected warehouse will be disabled, and you can only move products between warehouses using the "Entre Warehouse" operation.

To ensure that employees cannot move products directly without using the "Entre Warehouse" operation, you can create a custom security group that only allows access to the "Entre Warehouse" operation and assign it to the relevant employees.

To create a custom security group, follow these steps:

Go to the Settings module and select the menu "Users & Companies -> Security -> Groups".
Click on the "Create" button to create a new group.
Give the group a name, such as "Entre Warehouse Access".
In the "Access Rights" tab, select the "Warehouse Operations" application and deselect all the options except for the "Entre Warehouse" operation.
Save the changes and assign the new group to the relevant employees.

With these steps, only employees belonging to the "Entre Warehouse Access" group will be able to access the "Entre Warehouse" operation, and internal transfers between warehouses will be restricted.

That's a great idea! Restricting internal transfers between warehouses is a great way to ensure that products are moved through the correct channels and not mishandled. By using an Entre Warehouse operation, you can be sure that products are tracked and accounted for correctly.