autocde2.0/app/Http/Resources/API/AssetResource.php

<?php

namespace App\Http\Resources\API;

use Illuminate\Http\Request;
use Illuminate\Http\Resources\Json\JsonResource;

class AssetResource extends JsonResource
{
    protected int $level = 1;

    public function __construct($resource, int $level = 0)
    {
        parent::__construct($resource);

        $this->level = $level + 1;
    }

    /**
     * Transform the resource into an array.
     *
     * @return array<string, mixed>
     */
    public function toArray(Request $request): array
    {
        return [
            'id' => $this->id,
            'name' => $this->name,
            'code' => $this->code,
            'description' => $this->description,
            'status' => $this->status,
            'created_by' => $this->created_by,
            'owner' => $this->owner,
            'address' => $this->address,
            'group_id' => $this->group_id ?? 0,
            'geo_address_code' => $this->geo_address_code,
            'acl' => $this->acl,
            'whitelist' => $this->whitelist,
            'latitude' => $this->latitude,
            'longitude' => $this->longitude,
            'parent_id' => $this->parent_id,
            'level' => $this->level,
            'children' =>  $this->when($this->children->isNotEmpty(), function () {
                return $this->children->map(function ($child) {
                    return new AssetResource($child, $this->level);
                })->all();
            }),
        ];
    }
}