How can I retrieve a layout from child theme without affecting my live site?

If you’ve made changes to your live site after performing the demo content import and deleted some layouts or demo content, but now need to retrieve specific layouts or sections from the demo content, follow these steps:

Set Up a Staging Site:
Create a staging site where you can safely make changes without impacting your live site.
Perform Demo Import on Staging Site:
Install and activate the child theme on the staging site. Then, perform the demo import to restore all layouts and data without affecting your live environment.
https://diviextended.com/divi-portability-how-to-import-and-export-divi-settings-templates-pages-layouts/
Export Data from Staging Site:
After completing the demo import on the staging site, export the required layouts or sections that you wish to restore.
Import Data to Main Site:
Use the exported data from the staging site and import it into your live site. This allows you to retrieve specific layouts without overwriting or affecting other customizations on your main site.