如果要添加自定义data 由生成的菜单的属性wp_nav_menu 作用您可以使用nav_menu_link_attributes 筛选以将所需属性添加到<a> 元素。

function add_menu_atts( $atts, $item, $args ) {
    $atts[\'data-hover\'] = $atts[\'title\']; // add data-hover attribute

    return $atts;
}
add_filter( \'nav_menu_link_attributes\', \'add_menu_atts\', 10, 3 );

You can also try:

/*
 * Add filter attribute 
 */

add_filter( \'walker_nav_menu_start_el\', \'modify_walker_data_attr\', 10, 4);

function modify_walker_data_attr( $item_output, $item, $depth, $args )
{

    // I use ACF for adding field to a menu item
    // https://www.advancedcustomfields.com/resources/adding-fields-menu-items/
    $data_hover = get_field(\'data-hover\', $item);

    $old = \'<a\';
    $new = \'<a data-hover="\'.$data_hover.\'" \';

    $item_output = str_replace($old, $new, $item_output);

    return $item_output;
}