Customize SearchWP's lenient accent conversion to only utilize Greek letters

functions.php

<?php

function my_searchwp_leinent_accents_conversions() {
	return array(
		// Only convert Greek
		'Ά' => 'Α', 'ά' => 'α', 'Έ' => 'Ε', 'έ' => 'ε', 'Ή' => 'Η', 'ή' => 'η', 'Ί' => 'Ι', 'ί' => 'ι', 'Ό' => 'Ο', 'ό' => 'ο', 'Ύ' => 'Υ', 'ύ' => 'υ', 'Ώ' => 'Ω', 'ώ' => 'ω', 'ϊ' => 'ι', 'ϋ' => 'υ', 'Ϊ' => 'ι', 'Ϋ' => 'Υ',
	);
}

add_filter( 'searchwp_leinent_accents_conversions', 'my_searchwp_leinent_accents_conversions' );