[083n]

I solved it with my own effort.

function bp_remove_nav_item() {
    $current_user   = wp_get_current_user();
    $role_name      = $current_user->roles[0];
    if($role_name==='administrator'){
       bp_core_remove_nav_item( 'buddyblog' );
    }
}
add_action( 'wp', 'bp_remove_nav_item' );

This code delete blog menu for administrator.