FunctionsPublic/Find-GraphGroupByName.ps1

function Find-GraphGroupByName
{
    param(
        [psobject]$accessToken, 
        [string]$displayName
    )
    
    #
    # Escape special characters in displayName and get corresponding
    # group by using its name.
    #
    $responseBody = Invoke-RestMethod -Uri "https://graph.microsoft.com/beta/groups?`$filter=displayName eq '$([System.Web.HttpUtility]::UrlEncode($displayName))'" `
        -Headers @{"Authorization" = "Bearer $($accessToken.AccessTokenCredential.GetNetworkCredential().password)"} 

    if($null -eq $responseBody.value)
    {
        return $null
    }
    else
    {
        return $responseBody.value
    }
}