Confirm Sub-Requirements behaviourBy default Xray will have the following settings enabled:

This means that a Requirement can be associated with Sub-Requirements, resulting in a hierarchy of Requirement issues. With these options enabled, you will have this behaviour by just using the relation: - Issue > Sub-Task - For example using issue types like "Requirement" & "Sub-Requirements"
- Epic > Story
To have "Sub-Tasks / Links" working correctly, you need to have the Sub-Task requirement issue types associated with "Requirements" in the "Issue Type Mapping" section. For example, you can create a new issue type Sub-Requirement / Sub-Story and mapped as a Requirement. |
If you decide to disable these options, you can set the sub-requirement behaviour using the Jira linking mechanism. You just need to select which "Issue Link Type" to use and the correct "Direction.

A Jira re-index operation is recommended when there are changes to Issue Type Mappings. |
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