$product_ids = apply_filters( 'mam_wc_make_an_offer_products', array() );

Return an array of WooCommerce product IDs to scope the offers screen. When the array is non-empty, the Received Offers view lists only offers whose product is in the set; an empty array (the default) means no limit.

The MAM WooCommerce Product Vendors plugin consumes this filter to scope the offer list on marketplace sites.

Example: offers only on one category

add_filter( 'mam_wc_make_an_offer_products', function ( $ids ) {
    $q = new WP_Query( array(
        'post_type'      => 'product',
        'fields'         => 'ids',
        'posts_per_page' => -1,
        'tax_query'      => array( array(
            'taxonomy' => 'product_cat',
            'field'    => 'slug',
            'terms'    => 'negotiable',
        ) ),
    ) );
    return array_merge( $ids, $q->posts );
} );