BuddyPress – Search members by name and also by username

Somebody on the BuddyPress support forums had this to say:

I don’t recommend to change the core files of buddypress. The best way
to do it is to write a custom code (I don’t know how to guide you). So
if you don’t mind changing the core files, here is a quick way.

Open /buddypress/bp-core/bp-core-classes.php and change the

$sql['where_searchterms'] = “AND pd.value LIKE ‘%%$search_terms%%’”;

to

$sql['where_searchterms'] = “AND (pd.value LIKE ‘%%$search_terms%%’ OR 
    u.user_login LIKE’%%$search_terms%%’)” ;

If someone can guide us how to do it in bp-custom.php, it would be
great.