How to Hide Standard Button in Salesforce Community Builder using javascript?

Hi Amresh,

Following code is to hide search bar in the community through javascript, with the reference of this code you may hide standard button too.

<script src="<a href="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js" target="_blank" rel="nofollow">https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js</a&gt;" type="text/javascript"></script>
<script>
/* Hide the top search box */
var j$ = jQuery.noConflict();
j$(document).ready(function(){
j$(".searchCell").hide();
});
</script>

In place of ".searchCell" class, you need to put your button class here.

Hope this helps you.