Create users of OU

How do i add all my Organization Unit members to one newly created group…?
I can’t add them manually because 500+ users in my OU.
And If i create a new user in that OU it should get automatically replicate to group.
Is there any powershell script for this?
Any other solution ? please help !!

https://social.technet.microsoft.com/Forums/de-DE/e2f6d388-7ea4-4586-a098-48321b41d8ff/how-do-i-add-all-my-organization-unit-members-to-one-newly-created-group-i-cant-add-them?forum=winserverpowershell