Hi Vladimir,
Thanks for reaching out to us here on our support forum.
So what you should look at a filter: ‘tribe-events-bar-filters’
You will need to remove the current field then add new one.
if ( class_exists( 'Tribe__Events__Events' ) ){
$instances['tec'] = Tribe__Events__Events::instance();
} else {
$instances['tec'] = TribeEvents::instance();
}
remove_filter( 'tribe-events-bar-filters', array( $instances['tec'], 'setup_keyword_search_in_bar' ), 1, 1 );
add_filter( 'tribe-events-bar-filters', 'new_field_function_filters', 10, 1 );
If there is any questions feel free to ask, but this will require development knowledge.
My Best Regards,