Compound Dynamic Parameters in Powershell

I am attempting to use two Dynamic Parameters in the same cmdlet. The problem is that I would like the second dynamic parameter to use the first parameter to populate the result set.

For example the syntax for using the command could be something like this -

Get-MSRP -Manufacturer Jeep -Trim Rubicon

'Manufacturer' is a dynamic parameter that looks at a file on the disk to populate values for the user. I would 'Trim' to consume the 'Manufacturer' option that the user chose to create a result set of 'Trim'.

My 'Manufacturer' is working correctly but I believe that the value which the user has chosen isn't available when the code for the DynamicParam I've created for 'Trim', has been ran.

Any help?

function Get-MSRP{
    [cmdletbinding()]
    param()
    DynamicParam{
        $Param1 = "Manufacturer",0,{GC c:\temp\manufacturers.txt},$False
        $Param2 = "Trim",1,{GC c:\temp\$Manufacturer\Trim.txt},$False
        Get-DynamicParameterSet $Param1,$Param2
    }
    begin{
        $Manufacturer = $PSBoundParameters["Manufacturer"]
        $Trim = $PSBoundParameters["Trim"]
    }
    process{
        return Invoke-Sqlcmd -Database 'db' -ServerInstance 'server' -Query 
        "Select MSRP from pricing.MSRP where Manufacturer = '$Manufacturer' 
        and Trim = '$Trim'"
    }
}


function Get-DynamicParameterSet{
    param($Params)
    $RuntimeParameterDictionary = New-Object 
System.Management.Automation.RuntimeDefinedParameterDictionary
    if($Params[0].GetType().Name -eq "String" ){
        Write-Debug "Single Param to build"
        $RuntimeParameterDictionary = BuildSet $Params[0] $Params[1] 
$([Scriptblock]$Params[2]) $Params[3] $Params[4] $RuntimeParameterDictionary
    }else{
        foreach($Param in $Params){
            $RuntimeParameterDictionary = BuildSet $Param[0] $Param[1] 
            $([Scriptblock]$Param[2]) $Param[3] $Param[4] 
            $RuntimeParameterDictionary
        }
    }
    return $RuntimeParameterDictionary
}

function BuildSet{
    param(
        $ParameterName,
        [int]$Position,
        [ScriptBlock]$scriptBlock,
        $Mandatory,
        $SetNames,
          [System.Management.Automation.RuntimeDefinedParameterDictionary]$RuntimeParameterDictionary)

    Write-Debug "Setting up $ParameterName"
    $AttributeCollection = New-Object System.Collections.ObjectModel.Collection[System.Attribute]

    $ParameterAttribute = New-Object System.Management.Automation.ParameterAttribute
    $ParameterAttribute.Mandatory = $Mandatory
    $ParameterAttribute.Position = $Position
    $ParameterAttribute.ParameterSetName = $SetNames

    $AttributeCollection.Add($ParameterAttribute)
    Write-Debug "Generating result set"
    $arrSet = Invoke-Command $scriptBlock
    Write-Debug "Generated as $arrSet"
    $ValidateSetAttribute = New-Object System.Management.Automation.ValidateSetAttribute($arrSet)

    $AttributeCollection.Add($ValidateSetAttribute)

    $RuntimeParameter = New-Object System.Management.Automation.RuntimeDefinedParameter($ParameterName, [string], $AttributeCollection)
    $RuntimeParameterDictionary.Add($ParameterName, $RuntimeParameter)
    return $RuntimeParameterDictionary

}

Minimal & Verifiable

function Get-MSRP{
    [cmdletbinding()]
    param()
    DynamicParam{
        $Param1 = "Manufacturer",0,{GC c:\temp\manufacturers.txt},$False
        $Param2 = "Trim",1,{gci c:\temp\$Manufacturer},$False
        Get-DynamicParameterSet $Param1,$Param2
    }
    begin{
        $Manufacturer = $PSBoundParameters["Manufacturer"]
        $Trim = $PSBoundParameters["Trim"]
    }
    process{
        return Invoke-Sqlcmd -Database 'db' -ServerInstance 'server' -Query 
        "Select MSRP from pricing.MSRP where Manufacturer = '$Manufacturer' 
        and Trim = '$Trim'"
    }
}


function Get-DynamicParameterSet{
   param($Params)

   $RuntimeParameterDictionary = [System.Management.Automation.RuntimeDefinedParameterDictionary]::new()
   foreach($Param in $Params){

        $ParameterName = $Param[0]
        [int]$Position = $Param[1]
        [ScriptBlock]$scriptBlock = $([Scriptblock]$Param[2])
        $Mandatory = $Param[3]
        $SetNames =$Param[4]

        $AttributeCollection = [System.Collections.ObjectModel.Collection[System.Attribute]]::new()

        $ParameterAttribute = [System.Management.Automation.ParameterAttribute]::new()
        $ParameterAttribute.Mandatory = $Mandatory
        $ParameterAttribute.Position = $Position
        $ParameterAttribute.ParameterSetName = $SetNames

        $AttributeCollection.Add($ParameterAttribute)

        $arrSet = Invoke-Command $scriptBlock

        $ValidateSetAttribute = New-Object System.Management.Automation.ValidateSetAttribute($arrSet)

        $AttributeCollection.Add($ValidateSetAttribute)

        $RuntimeParameter = New-Object System.Management.Automation.RuntimeDefinedParameter($ParameterName, [string], $AttributeCollection)
        $RuntimeParameterDictionary.Add($ParameterName, $RuntimeParameter)
    }
    return $RuntimeParameterDictionary
}