i inserted this code, and nothing showsup on the frontend expert block
<?php
$experts = get_users( 'fields=ID&role=expert' );
$args = array(
'include' => $experts,
'per_page' => 500 // the number of members that you have
);
if ( bp_has_members( bp_ajax_querystring( 'members' ) . '&per_page=500&include=' . $experts ) ) :
while ( bp_members() ) : bp_the_member();
?>