if( $user->getAttr( 'username' ) eq $filter->{'username'} )

##</code><code>##

&{$filter->{$field}->{'filterCallback'}}( $recordObj )

##</code><code>##

$queryObj->filter( 'field' => 'username', $objList => \@records, 'callBack' => sub { $_[0]->getAttr( 'username' ) eq $value ) } )