show all categories except one in dynamic tabs

How to show all categories except one in dynamic tabs? For example: recent posts in dynamic tabs. in the drop-down menu we can choose category All/category1/category2/category8. What if I want to hide category8 in recent posts?
I’ve already excluded category8 from my front page using this code

function dc_exclude_category( $query ) {
    if ( $query->is_home() && $query->is_main_query() ) {
        $query->set( 'cat', '-8' );
    }
}
add_action( 'pre_get_posts', 'dc_exclude_category' );