Sitecore PowerShell - Merge Layouts

Below script will help you to merge content from layouts. PowerShell script will merge layout from Final to Shared. In the script we need to specify template id for which layouts needs to be merged.

Script

$query = "fast:/sitecore/content//*[@@templateid='{CC44DB9D-1111-4E8E-9D84-080CD8895C77}']"
Get-Item -Path "master:" -Query $query | Merge-Layout

You can customize the script as per your requirement and use it. 

Hope this information is useful to you.