Functions/Public/Remove-MsGGroupMember.ps1

function Remove-MsGGroupMember {
    <#
    .SYNOPSIS
    Removes a member from a group in Entra ID.
    .DESCRIPTION
    This function removes specified members from the group in Entra ID.
    .PARAMETER DisplayName
    Display Name of the group.
    .PARAMETER ObjectId
    Object Id of the group.
    .PARAMETER UserPrincipalName
    The UserPrincipalName of the user to remove from the group.
    .PARAMETER DirectoryObjectId
    The Directory Object Id of the principal to remove from to the group.
    .PARAMETER Force
    Bypasses the confirmation check.
    .PARAMETER Headers
    Authentication Headers to connect to Microsoft Graph.
    .PARAMETER Jwt
    Jwt to connect to Microsoft Graph.
    .EXAMPLE
    PS> Remove-MsGGroupMember -DisplayName FinanceTeam -UserPrincipalName benjamin.cohn@testdomain.com -Force

    Removes the user "benjamin.cohn@testdomain.com" as a member from the FinanceTeam group.
    #>

    [CmdletBinding(SupportsShouldProcess)]
    param(
        [parameter(Mandatory = $true, ParameterSetName = 'Name', Position = 0, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)][string]$DisplayName,
        [parameter(Mandatory = $true, ParameterSetName = 'ObjId', Position = 1)][string]$ObjectId,
        [parameter(Mandatory = $false, Position = 2)][string[]]$UserPrincipalName,
        [parameter(Mandatory = $false, Position = 3)][string[]]$DirectoryObjectId,
        [parameter(Mandatory = $false)][switch]$Force,
        [parameter(Mandatory = $false)][hashtable]$Headers,
        [parameter(Mandatory = $false)][string]$Jwt
    )
    BEGIN {
        # Session Checks
        if ([string]::IsNullOrEmpty($Headers) -and [string]::IsNullOrEmpty($Jwt)) {
            if ($null -ne $myGraphToken) {
                Write-Verbose "Setting Jwt to Global: $myGraphToken"
                $Jwt = $myGraphToken
            }
        }
        if ([string]::IsNullOrEmpty($Headers) -and -not([string]::IsNullOrEmpty($Jwt))) {
            $Headers = @{
                'Authorization' = 'Bearer {0}' -f $Jwt
                'Content-Type'  = 'application/json'
            }
        }
        if ([string]::IsNullOrEmpty($Headers)) {
            $errorMessage = '{0} : Unable to run command. Headers are empty.' -f $MyInvocation.MyCommand.Name
            throw $errorMessage
        }

        $irmParams = @{
            'Headers'     = $Headers
            'ErrorAction' = 'Stop'
        }
        # end Session Checks
    }
    PROCESS {
        # Retrieve group from Entra ID
        try {
            switch ($PSCmdlet.ParameterSetName) {
                "Name" {
                    $groupEndpoint = "groups?`$filter=displayName eq '{0}'" -f $DisplayName
                }
                "ObjId" {
                    $groupEndpoint = "groups/{0}" -f $ObjectId
                }
            }
            $group = Invoke-MsGRequest -Method Get -Endpoint $groupEndpoint @irmParams
            if ([string]::IsNullOrEmpty($group)) {
                $errorMessage = 'Group not found.'
                throw $errorMessage
            }
        }
        catch {
            $errorMessage = Get-MsGErrorMessage $_
            $errorException = '{0} : Unable to retrieve group from Entra ID. Error: {1}' -f $MyInvocation.MyCommand.Name, $errorMessage
            throw $errorException
        }
        # end region

        # Retrieve Members
        try {
            $groupMembers = Get-MsGGroupMember -ObjectId $group.id @irmParams
            $memberIDsToRemove = $groupMembers | Where-Object { $_.userPrincipalName -in $UserPrincipalName -or $_.id -in $DirectoryObjectId } | Select-Object -ExpandProperty id
        }
        catch {
            $errorMessage = Get-MsGErrorMessage $_
            $errorException = '{0} : Unable to validate group members from Entra ID. Error: {1}' -f $MyInvocation.MyCommand.Name, $errorMessage
            throw $errorException
        }
        # end region

        # Remove Members
        foreach ($memberId in $memberIDsToRemove) {
            if (($PSCmdlet.ShouldProcess($memberId, 'Remove Group Member')) -and ($Force.IsPresent -or ($PSCmdlet.ShouldContinue("Remove '$memberId' as an member from '$($group.displayName)'.", 'Are you sure you want to proceed?')))) {
                $memberEndpoint = 'groups/{0}/members/{1}/$ref' -f $group.id, $memberId
                try {
                    Invoke-MsGRequest -Method Delete -Endpoint $memberEndpoint -Body $body @irmParams > $null
                }
                catch {
                    $errorMessage = Get-MsGErrorMessage $_
                    $errorException = 'Unable to remove {0} as an member from the group. Error: {1}' -f $memberId, $errorMessage
                    Write-Error $errorException
                    continue
                }
            }
        }
        # end region
    }
}