# input the users email address you want to copy from
$source = "user1@domain.com.au"

# input the users email address you want to paste the groups to
$destination = "user2@domain.com.au"

Connect-ExchangeOnline

$dn = (Get-EXOMailbox $source).DistinguishedName

Get-EXORecipient -Filter "Members -eq '$dn'" -RecipientTypeDetails GroupMailbox | ForEach-Object { Add-UnifiedGroupLinks $_.Name -LinkType Member -Links $destination }
Get-EXORecipient -Filter "Members -eq '$dn'" -RecipientTypeDetails MailUniversalDistributionGroup | ForEach-Object { Add-DistributionGroupMember $_.Name -Member $destination }