Multiple categories on adverts_list or single URL

Hi,
we do not have such function in the [adverts_list] by default, but you can add the code below in your theme functions.php file or create a new blank WP plugin and paste it there

add_filter( "shortcode_atts_adverts_list", "adverts_list_search_by_multi_category_atts", 10, 3 );
add_filter( "adverts_list_query", "adverts_list_search_by_multi_category_param", 10, 2 );
function adverts_list_search_by_multi_category_atts( $out, $pairs, $att ) {
    $out["_multicat"] = "";
    if(isset($att["_multicat"])) {
        $out["_multicat"] = $att["_multicat"];
    }
    return $out;
}
function adverts_list_search_by_multi_category_param($args, $params) {
    if(!empty($params["_multicat"])) {
        if(!is_array($args["tax_query"])) {
            $args["tax_query"] = array();
        }
        $args["tax_query"][] = array(
            'taxonomy' => 'advert_category',
            'field'    => 'term_id',
            'terms'    => array_map( "trim", explode( ",", $params["_multicat"])),
        );
    }
    return $args;
}

then you should be able to use the [adverts_list] like this

[adverts_list columns="3" posts_per_page="40" _multicate="165,166,167"]

where 165,166,167 are the IDs of categories.

Thanks!