The easiest way to do it would be to set the display to none in css for the search form,as follows:

.ow_console_body.console_item.common_shortcuts {

display:none;

}

You would do this directly in the join_index.html file which is located in /ow_system_plugins/view/controllers/join_index.html

So your code at the top would go like this:

{style} {literal}

.ow_console_body.console_item.common_shortcuts {display:none;}

{/literal} {/style}

It may be different depending upon what theme you use, but this should definitely help - it's what I use.

Edward, you need to contact plugin developer directly to get this info. 

okay rose  my plugin is " ocs advance user search + site search "

i just want hide for guest ( join page ) but there are not option at current version to hide at join page ..