Code to import only certain brands - By WebToffee (Product import export basic)

functions.php

<?php>//Do not copy this line of code
 add_filter('wt_iew_importer_do_import_basic', 'filter_products_by_brand', 1, 4);

function filter_products_by_brand($data_arr, $to_process, $step, $selected_template_data) {
    // Define allowed brands (normalized to uppercase and trimmed)
    $allowed_brands = array_map('strtoupper', array_map('trim', array('Brand1', 'Brand2', 'Brand3')));

    foreach ($data_arr as $key => $product) {
        if (isset($product['meta_mapping_fields']['taxonomies']['tax:product_brand'])) {
            $raw_brand = $product['meta_mapping_fields']['taxonomies']['tax:product_brand'];
            $normalized_brand = strtoupper(trim($raw_brand));

            if (!in_array($normalized_brand, $allowed_brands)) {
                unset($data_arr[$key]);
            }
        } else {
            // No brand found — exclude the product
            unset($data_arr[$key]);
        }
    }

    return $data_arr;
}