Adding If statement inside a loop in views

Hi, Long. Thanks for the reply.

I also tried that but still doesn't work. So basically the upload_documents is a group id for the first loop and the fields inside it are the project_documents. What I want to achieve is to see, if data of project_documents is empty then do something if not then do this. Thanks in advance.

Here's my custom fields setup:

<?php
add_filter( 'rwmb_meta_boxes', 'your_prefix_function_name' );

function your_prefix_function_name( $meta_boxes ) {
    $prefix = '';

    $meta_boxes[] = [
        'title'      => __( 'Project Details', 'your-text-domain' ),
        'id'         => 'project-details',
        'post_types' => ['project'],
        'geo'        => [
            'api_key' => 'AIzaSyCxo8eTReDw2Ehp9zYovWw4W9VRwEsD8Cs',
        ],
        'fields'     => [
            [
                'id'   => $prefix . 'custom_html_2avzqnhkuwl',
                'type' => 'custom_html',
                'std'  => 'To upload images in this project, please go to the right sidebar and find the Project Image.',
            ],
            [
                'name'              => __( 'Project Documents', 'your-text-domain' ),
                'id'                => $prefix . 'upload_documents',
                'type'              => 'group',
                'collapsible'       => true,
                'save_state'        => true,
                'group_title'       => '{project_documents}',
                'clone'             => true,
                'sort_clone'        => true,
                'clone_as_multiple' => true,
                'add_button'        => __( 'Upload more', 'your-text-domain' ),
                'before'            => __( 'מסמכי הפרויקט', 'your-text-domain' ),
                'fields'            => [
                    [
                        'name' => __( 'Add Thumbnail Icon', 'your-text-domain' ),
                        'id'   => $prefix . 'document_icon',
                        'type' => 'single_image',
                    ],
                    [
                        'name'             => __( 'Add Document', 'your-text-domain' ),
                        'id'               => $prefix . 'project_documents',
                        'type'             => 'file_advanced',
                        'max_file_uploads' => 1,
                    ],
                ],
            ],
            [
                'name'   => __( 'Project Address', 'your-text-domain' ),
                'id'     => $prefix . 'project_address_bar',
                'type'   => 'text',
                'before' => __( 'כתובת הפרויקט', 'your-text-domain' ),
            ],
            [
                'name'   => __( 'Project Map', 'your-text-domain' ),
                'id'     => $prefix . 'project_map_group',
                'type'   => 'group',
                'before' => __( 'מפת הפרויקט', 'your-text-domain' ),
                'fields' => [
                    [
                        'name'   => __( 'Address Name', 'your-text-domain' ),
                        'id'     => $prefix . 'address_name',
                        'type'   => 'text',
                        'before' => __( 'כתובת', 'your-text-domain' ),
                    ],
                    [
                        'name'          => __( 'Map', 'your-text-domain' ),
                        'id'            => $prefix . 'osm_map',
                        'type'          => 'osm',
                        'address_field' => 'address_name',
                        'language'      => 'en',
                        'region'        => 'il',
                        'before'        => __( 'מַפָּה', 'your-text-domain' ),
                    ],
                ],
            ],
        ],
    ];

    return $meta_boxes;
}

Hi, I don't have problems showing the item, my problem is how can I put an if statement inside a loop or condition if it is empty.

{% for clone in post.upload_documents %}
    {% for item in clone.project_documents %}
        {% if item.url is empty %}
        <h3>empty</h3>
        {% else %}
        <h3>{{ item.url }}</h3>
        {% endif %}
    {% endfor %}
{% endfor %}