$category $ post_1 merged

$category = 'Chemical Engineer'
$post_1 = Chemical Engineer, AO, JE, Clerk, MTS

Then

Final Result will be Chemical Engineer, AO, JE, Clerk, MTS
Why Needed?
On Chemical Engineering Jobs Page
I want to show the profile Chemical Engineer first then other jobs follows.

<?php
$category = $listing->keyField('cat_1');
?>

<?php if (!$recommendedListings->isEmpty()): ?>

    <?php foreach ($recommendedListings as $recommendedListing): ?>
        <?php if ($recommendedListing->id != $listing->id): ?>

            <li>
                <a class="d-block" href="<?= route()->url('frontend.listings.show', ['id' => $recommendedListing->generateSlug()]) ?>">
                    <?= $recommendedListing->keyField('org_1') ?>
                    <?= $category . ', ' . implode(', ', array_filter(array_map(function ($p) use ($category) {
                        $c = strtolower(str_replace(['-', '_'], ' ', trim($p)));
                        return $c != strtolower($category) ? trim($p) : null;
                    }, explode(',', $recommendedListing->keyField('post_1'))))) ?>
                    Recruitment 2026
                    <!--<?= $recommendedListing->keyField('total_vacancy') . ' ' . $recommendedListing->keyField('post_2') . ' ' . ((int)$recommendedListing->keyField('total_vacancy') === 1 ? 'Vacancy' : 'Vacancies') ?>-->
                </a>
            </li>
        <?php endif; ?>
    <?php endforeach; ?>

<?php endif; ?>