Related issues are a bi-directional relationship between any two issues and appear in a block below the issue description. Issues can be across groups and projects.
The relationship only shows up in the UI if the user has write permissions
to see both issues (
You can relate one issue to the other by clicking the issue count badge "+" button in the header of the related issue block. Then use the input that will appear where you can type in the issue reference or paste in a link to an issue.
Valid references will be added to a temporary list that you can review. When ready, click the green "Add related issues" button to submit.
In the related issues block, click the "x" icon on the right-side of every issue token. Because of the bi-directional relationship, it will no longer appear in either issue.