> For the complete documentation index, see [llms.txt](https://guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guardian.hedera.com/docs/develop/guardian/workspace/schemas/cross-schema-conditions/configure-nested-and-cross-schema-conditions.md).

# Configure Nested and Cross-Schema Conditions

Set up a condition where the trigger field, the controlled fields, or both live inside referenced sub-schemas.

### Prerequisites

* The schema you are editing already has at least one field of type **Sub-Schema** referencing a loaded sub-schema.
* For cross-schema conditions, you need at least two Sub-Schema fields referencing different sub-schemas.

### Steps

#### Use a nested field as the IF trigger <a href="#use-a-nested-field-as-the-if-trigger" id="use-a-nested-field-as-the-if-trigger"></a>

1. Open the schema editor and scroll down to the **Conditions** section.
2. Click **Add Condition**.
3. Open the IF field picker. Fields are grouped: **This Schema** at the top, then one group per referenced sub-schema labelled with the sub-schema's name.
4. Select a field from one of the sub-schema groups.
5. Enter the match value in the field to the right of the picker.
6. Add THEN and ELSE fields using **Add THEN Field** and **Add ELSE Field** as normal.
7. Save the schema.

#### Add cross-schema targets to a THEN or ELSE branch <a href="#add-cross-schema-targets-to-a-then-or-else-branch" id="add-cross-schema-targets-to-a-then-or-else-branch"></a>

Continue from step 5 above, or open an existing condition that already has a nested IF field set.

6. Below the THEN fields area, open the **Add sub-schema THEN field or Add sub-schema ELSE field** dropdown and select a field from a sub-schema. That field appears when the condition is true. It appears as a **Sub-schema THEN** chip on the condition row.
7. Repeat for any additional target fields across other sub-schemas.
8. Save the schema.

{% hint style="info" %}
Sub-schema THEN alone already hides the target field in the form when the condition does not match.
{% endhint %}

### Result

When a user fills in the parent form:

* The condition from the IF field is taken from the target sub-schema.
* When its value matches: **Sub-schema THEN** or **Sub-schema ELSE** target fields appears in form.
* When its value does not match: **Sub-schema THEN** or **Sub-schema ELSE** target fields are hidden and must not be submitted.

### Troubleshooting

**Sub-schema fields do not appear in the IF picker.**\
The sub-schema must be fully loaded in the editor. If a group is missing, check that the Sub-Schema field has a valid schema type assigned and that the referenced schema is available in your policy context.

### Related

* Concept: [Cross-Schema Conditions](/docs/develop/guardian/workspace/schemas/cross-schema-conditions.md)
* Task: [Creating Schema using UI](/docs/develop/guardian/workspace/schemas/creating-system-schema-using-ui.md)
* Reference: [Conditional and Visibility Logic](/docs/develop/guardian/workspace/schemas/best-practices-to-implement-schema/conditional-and-visibility-logic.md)


---

# 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 dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://guardian.hedera.com/docs/develop/guardian/workspace/schemas/cross-schema-conditions/configure-nested-and-cross-schema-conditions.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.