lib/Get-2ndCompletions.ps1

function Get-2ndCompletions([string] $WordToComplete, [string] $Command) {
    if (-not $commandValues) {
        . $PSScriptRoot\..\values.ps1
    }
    if (-not $subCommands) {
        . $PSScriptRoot\..\subCommands.ps1
    }

    $searchBlock = { $_ -like "$WordToComplete*" }
    $completions = @()

    # Command's values
    if ($commandValues[$Command]) {
        $completions += Invoke-Command -ScriptBlock $commandValues[$Command] -ArgumentList @($WordToComplete) | ForEach-Object {
            [System.Management.Automation.CompletionResult]::new($_, $_, 'DynamicKeyword', $_)
        }
    }

    # Sub-commands
    if ($subCommands[$Command]) {
        $completions += $subCommands[$Command].Keys | Where-Object $searchBlock | ForEach-Object {
            [System.Management.Automation.CompletionResult]::new($_, $_, 'Command', $_)
        }
    }

    return $completions
}