Multiple parameter sets and PowerShell

Question

I am building a function which will have three distinct parameter sets, and two of those sets will overlap with the third. The options would look like this:

Answer 1

By adding two more Parameter Sets you can do what you want. This is needed because you have 3 sets now, plus a non-set parameter (which technically puts it in the __AllParameterSets set if I remember right). So that's 4 ways of doing it. You need 6 ways of doing it if I am reading your question correctly. You want all of the following options:

Move-AccountOut -Username   []
Move-AccountOut -Username  [-RetainGroups] [-TransferHomeDrive] [-OldServer ] [-NewServer ]  []
Move-AccountOut -Username  [-RetainGroups]  []
Move-AccountOut -Username  [-RemoveFromAllGroups] [-TransferHomeDrive] [-OldServer ] [-NewServer ]  []
Move-AccountOut -Username  [-RemoveFromAllGroups]  []
Move-AccountOut -Username  -OldServer  -NewServer  [-TransferHomeDrive]  []

So we will add the RemoveFromAllGroupsWTran and RetainGroupsWTran Parameter Sets, add them both to $TransferHomeDrive, $OldServer, and $NewServer (removing the other related set names from them), then add each to its respective switch parameter. It ends up looking like this:

function Move-AccountOut {

    [CmdletBinding(DefaultParameterSetName='NoTransferHomeDrive')]
    Param( 
        [Parameter(Mandatory=$True, ValueFromPipeline=$True, ValueFromPipelineByPropertyName=$True)]
        [string]$Username,

        [Parameter(ParameterSetName='RetainGroups')]
        [Parameter(ParameterSetName='RetainGroupsWTran')]
        [switch]$RetainGroups,

        [Parameter(ParameterSetName='RemoveFromAllGroups')]
        [Parameter(ParameterSetName='RemoveFromAllGroupsWTran')]
        [switch]$RemoveFromAllGroups,

        [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$False)]
        [Parameter(ParameterSetName='RetainGroupsWTran')]
        [Parameter(ParameterSetName='RemoveFromAllGroupsWTran')]
        [switch]$TransferHomeDrive,

        [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$True)]
        [Parameter(ParameterSetName='RetainGroupsWTran')]
        [Parameter(ParameterSetName='RemoveFromAllGroupsWTran')]
        [string]$OldServer,

        [Parameter(ParameterSetName='TransferHomeDrive', Mandatory=$True)]
        [Parameter(ParameterSetName='RetainGroupsWTran')]
        [Parameter(ParameterSetName='RemoveFromAllGroupsWTran')]
        [string]$NewServer
    )
}