> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/cortex-xpanse/inventory/manage-business-units/business-unit-management-for-domains-and-subdomains.md). # Business Unit Management for Domains and Subdomains Learn how to manage business unit assignments for domains and subdomains. Any user-specified change to the business unit (BU) for a domain or subdomain is called an *override*. When you modify the BU for a domain, typically you have the option to change the BU for the domain only or for the domain and all related subdomains. There are two situations where you will not be able to update all or some of the related subdomains: * If a subdomain has a BU override that makes it different from the BU for the parent domain, then you cannot change the subdomain by selecting **Make changes to related subdomains**. In this case, before you confirm the BU updates you will see a dialog box indicating that all or some of the subdomains have already been reassigned to different BUs. If a domain and subdomains have the same BU assignment, you will be able to update the BU for the subdomains by selecting **Make changes to related subdomains**. And you can always update the BU for an individual domain or subdomain, regardless of whether it has been reassigned before. * If you don't have the right access permissions in Expander to view or modify subdomains, you will not be able to update the BU assignment. In this case, you will see a message in the dialog indicating that you do not have permission to update the subdomains. Click **Proceed Anyway** to update the BU for the domain only. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://cortex-docs.paloaltonetworks.com/cortex-xpanse/inventory/manage-business-units/business-unit-management-for-domains-and-subdomains.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.