Set-UserAndGroupMapping

# Create or update the user and group mapping
$mappingSettings = Set-UserAndGroupMapping -Source "John Doe" -Destination "Paul Smith"

$mappingSettings = Set-UserAndGroupMapping -MappingSettings $mappingSettings -Source "myusername" -Destination "anotherusername"

# Map unresolved users or groups to "Old employee Group"
$mappingSettings = Set-UserAndGroupMapping -MappingSettings $mappingSettings -UnresolvedUserOrGroup -Destination "Old employee Group"

# Display the current mapping settings
$mappingSettings
# Output:
# PropertyMappings        :
# ContentTypeMappings     :
# UserAndGroupMappings    :  <Unresolved users or groups> -> Old employee Group
#                            John Doe                     -> Paul Smith
#                            myusername                   -> anotherusername
# PermissionLevelMappings :
# SiteTemplateMappings    :

# Connect to the source and destination sites
$srcSite = Connect-Site -Url "http://myfarm1/sites/mysourcesite"
$dstSite = Connect-Site -Url "http://myfarm1/sites/mydestinationsite"

# Retrieve the current user and group mapping settings
$mappingSettings = Get-UserAndGroupMapping -SourceSite $srcSite -DestinationSite $dstSite

# Update the mapping to include "John Doe" -> "Paul Smith"
$mappingSettings = Set-UserAndGroupMapping -MappingSettings $mappingSettings -Source "John Doe" -Destination "Paul Smith"

# Update the mapping to include "myusername" -> "anotherusername"
$mappingSettings = Set-UserAndGroupMapping -MappingSettings $mappingSettings -Source "myusername" -Destination "anotherusername"

# Map unresolved users or groups to "Old employee Group"
$mappingSettings = Set-UserAndGroupMapping -MappingSettings $mappingSettings -UnresolvedUserOrGroup -Destination "Old employee Group"

# Display the final mapping settings
$mappingSettings
# Output:
# PropertyMappings        :
# ContentTypeMappings     :
# UserAndGroupMappings    :  <Unresolved users or groups> -> Old employee Group
#                            CustomPermissions Members    -> Sales&Marketing Owners
#                            i:0#.w|office\sg.achille     -> i:0#.w|office\sg.baptiste
#                            i:0#.w|office\sg.camille     -> i:0#.w|office\sg.denis
#                            John Doe                     -> Paul Smith
#                            myusername                   -> anotherusername
# PermissionLevelMappings :
# SiteTemplateMappings    :

Set-UserAndGroupMapping-Source <String>
-Destination <String>
[-MappingSettings] <MappingSettings>

Set-UserAndGroupMapping-Source <String>
-Ignore <SwitchParameter>
[-MappingSettings] <MappingSettings>

Set-UserAndGroupMappingUnresolvedUserOrGroup <SwitchParameter>
-Destination <String> 
[-MappingSettings <MappingSettings>]