Tell SearchWP to index term names from ACF (Advanced Custom Fields) Taxonomy fields

functions.php

<?php

// Tell SearchWP to index term names from ACF (Advanced Custom Fields) Taxonomy fields.
add_filter( 'searchwp_custom_fields', function( $meta_value, $meta_key, $the_post ) {
	$acf_taxonomy_field_names = array( 'mytaxfield1', 'mytaxfield2' );

	if ( ! in_array( $meta_key, $acf_taxonomy_field_names ) ) {
		return $meta_value;
	}

	// Retrieve the value as per ACF's field settings.
	$acf_field_object = get_field_object( $meta_key, $the_post->ID );

	// We want to index the chosen terms names.
	$meta_value = wp_list_pluck( $acf_field_object['value'], 'name' );

	return $meta_value;
}, 20, 3 );