Export a single backup definition:

Get-BEBackupDefinition –name |  Export-BEBackupDefinition > c:\.ps1

To export all definitions to a separate ps1 file:

 $jobs = Get-BEBackupDefinition
 foreach ($job in $jobs)
 {
                 $defname = $job.name
                 $job | Export-BEBackupDefinition > c:\$defname.ps1
               
 }

Import the backup definition:
& '' -AgentServer (Get-BEAgentServer "") | save-BEBackupdefinition

NOTES: Selection list are not exported and will need to be modified after import if needed. By default everything will be selected on the Selections.

This script is an example and is provided AS-IS. May require modification