gpnf-ignore-first-n-entries-in-count.php

<?php
/**
 * Gravity Perks // GP Nested Forms // Ignore the first `n` child entries with `:count` merge tag modifier
 * https://gravitywiz.com/documentation/gravity-forms-nested-forms
 *
 * Also works with `:total` merge tag modifier
 *
 * Instructions:
 *
 * 1. Install this snippet per https://gravitywiz.com/documentation/how-do-i-install-a-snippet/
 * 2. Install accompanying `gpnf-ignore-first-n-entries-in-count.php.js` JavaScript snippet: https://gist.github.com/matty0501/3c9d3d8e99417324bacb78bd7f13bc00
 * 3. Customize form ID, field ID(s), and `n` index
 */
add_filter( 'gpnf_calc_entries_PARENTFORMID_NESTEDFORMFIELDID', function ( $entries, $match, $nested_form_field, $form, $formula_field ) {
	// Only change what entries are used for the calculation done in parent field ID 3
	if ( rgar( $formula_field, 'id' ) != 3 ) {
		return $entries;
	}

	// Remove the first `n` entries, and return the modified array. Replace 2 with the number of entries you want to remove.
	$filtered_entries = array_slice( $entries, 2 );

	return $filtered_entries;
}, 10, 5 );