Step 1 – Restrict Role by Warehouse
Various admin users can be created and various Roles need to be assigned to these. In order to Restrict Role By Warehouses:-

• On Magento admin panel, System > Permissions > Roles.
• Choose the role to be edit, it will redirect to Role information > Role Resources. 
• Select Yes/No to restrict role by warehouse.

Step 2 – Assigning Warehouse to Admin User

• On Magento admin panel, System > Permissions > Users > User Information > User Info.
• Choose the admin user to edit, the selected attribute will be visible in admin user as well and then selected attribute value can be assigned to the user.
• The admin user will then be able to view orders related to the assigned attribute only.

Now if Admin User A is assigned the attribute of Warehouse A then he will be able to see only the orders related to Warehouse A only.