functions/Get-BBCourseMemberships.ps1

<#
.Synopsis
   Given a course ID, get all course enrollments.
.DESCRIPTION
   Long description
.EXAMPLE
   Get-BBCourses
   Get-BBCourseMemberships -CourseID '_11_' -Filter "role=Instructor&availability.available=Yes" -ExpandUser = $true
#>

function Get-BBCourseMemberships
{
    [CmdletBinding()]
    [Alias()]
    Param
    (

        [parameter(mandatory)][string]$CourseID,
        [string]$Filter,
        [bool]$ExpandUser=$false
    )

    Begin
    {

    }
    Process
    {
       if ($ExpandUser -eq $true){
          if ($Filter -eq ""){
            $Filter = "expand=user"
          }else {
             $Filter += "&expand=user"
          }

       }
        $apiurl = "/learn/api/public/v1/courses/$CourseID/users"
        Invoke-BBRestMethod -API $apiurl `
                    -Method Get `
                    -ContentType application/json `
                    -Filter $Filter
    }
    End
    {
    }
}