I use this command:
Set-SPOSiteGroup -Site htt.....com -Identity newgroup -Owner newgroup2
(newgroup is a Sharepoint group, newgroup2 is another sharepoint group)
Powershell responds with this: Set-SPOSiteGroup: The user newgroup2 was not found.
What is wrong with my command? I am sure newgroup2 exists, and i am able to make it the owner of newgroup using the sharepoint interface.
You can try with the following powershell code to set the group owner,
Add-PSSnapin Microsoft.Sharepoint.Powershell
#Get the SPWeb
$web = Get-SPWeb http://url_to_web
#Get the Group
$group1 = $web.SiteGroups["newgroup"]
#Get the Group
$group2 = $web.SiteGroups["newgroup2"]
#Assign Group as the owner
$group1.Owner = $group2
#Update the Group
$group1.Update()
Remove-PsSnapin Microsoft.SharePoint.PowerShell
Hope this helps you.
It's not possible to set an AD-group as an owner, but you can set a SharePoint group as owner as a workaround.
Reference: Set group owner using powershell
