Do you want to find all cmdlets with specific parameter? Since Windows PowerShell 3.0 you can use Get-Command -ParameterName.
PS C:\Windows\system32> gcm -ParameterName Domain
CommandType Name ModuleName ----------- ---- ---------- Cmdlet Add-Computer Microsoft.PowerShell.Management
But do not forget to import modules that should be searched.
PS C:\Windows\system32> ipmo ActiveDirectory, GroupPolicy PS C:\Windows\system32> gcm -ParameterName Domain
CommandType Name ModuleName ----------- ---- ---------- Alias Get-GPPermissions GroupPolicy Alias Set-GPPermissions GroupPolicy Cmdlet Add-Computer Microsoft.PowerShell.Management Cmdlet Backup-GPO GroupPolicy Cmdlet Get-ADReplicationFailure ActiveDirectory Cmdlet Get-ADReplicationPartnerMetadata ActiveDirectory Cmdlet Get-ADReplicationUpToDatenessVectorTable ActiveDirectory Cmdlet Get-GPInheritance GroupPolicy Cmdlet Get-GPO GroupPolicy Cmdlet Get-GPOReport GroupPolicy Cmdlet Get-GPPermission GroupPolicy Cmdlet Get-GPPrefRegistryValue GroupPolicy Cmdlet Get-GPRegistryValue GroupPolicy Cmdlet Get-GPStarterGPO GroupPolicy Cmdlet Import-GPO GroupPolicy Cmdlet New-GPLink GroupPolicy Cmdlet New-GPO GroupPolicy Cmdlet New-GPStarterGPO GroupPolicy Cmdlet Remove-GPLink GroupPolicy Cmdlet Remove-GPO GroupPolicy Cmdlet Remove-GPPrefRegistryValue GroupPolicy Cmdlet Remove-GPRegistryValue GroupPolicy Cmdlet Rename-GPO GroupPolicy Cmdlet Restore-GPO GroupPolicy Cmdlet Set-GPInheritance GroupPolicy Cmdlet Set-GPLink GroupPolicy Cmdlet Set-GPPermission GroupPolicy Cmdlet Set-GPPrefRegistryValue GroupPolicy Cmdlet Set-GPRegistryValue GroupPolicy
