acp-editing-value.php

<?php
/**
 * This hook allows you to alter the value that is retrieved for editing before it is displayed in the editable.
 */

/**
 * @param mixed     $value
 * @param int       $id
 * @param AC\Column $column
 *
 * @return mixed
 */
function acp_editing_value_example_usage( $value, $id, AC\Column $column ) {
	return $value;
}

add_filter( 'acp/editing/value', 'acp_editing_value_example_usage', 10, 3 );

// Or anonymous function

add_filter( 'acp/editing/view', function ( $value, $id, AC\Column $column ) {
	return $value;
}, 10, 3 );

/**
 * Example to get a nested value from an associative array. You need to parse it back when saving the value with the hook `acp/editing/save_value`
 *
 * @param mixed     $value
 * @param int       $id
 * @param AC\Column $column
 *
 * @return mixed
 */
function acp_editing_value_get_nested_value( $value, $id, AC\Column $column ) {
	if ( $column instanceof AC\Column\Customfield && 'my_custom_field_key' === $column->get_meta_key() ) {
		$value = $value['sub_key'];
	}

	return $value;
}

add_filter( 'acp/editing/value', 'acp_editing_value_get_nested_value', 10, 3 );