Click on icon to export subproject hierarchy to JSON file. You can import this JSON file to another Jira instance or to the same Jira instance.
Importing
To import a subproject hierarchy click on icon on top of the subproject hierarchy. This will open a file selector dialog, you can either select a previously exported JSON file or select a handcrafted file. But it's structure should match to the sample given above. Click on "Load" button to see a preview of import operation. Don't worry, you can still cancel operation after clicking on "Load". After clicking on "Load" following preview dialog will be displayed. Import operation will automatically create missing projects, update existing projects to match them to the information in JSON file. It will not delete any project even if it doesn't exist in the JSON file. But it will remove all project hierarchy and recreate it to match to the hierarchy specified in the JSON File.
To start import operation press the "Import" button. After the operation is completed you will need to "Acknowledge" operation and the page will be refreshed to show newly imported project hierarchy.