// Set your conditions here
// FIELD_KEY:OPTION_VALUE:FIELD_KEY_TO_SHOW
$conditions = [
    'destination:pelion:ekdromi Pelion',
    'destination:crete:ekdromi crete',
    'destination:rhodos:ekdromi rodos',
];

// DO NOT EDIT BELOW
JHtml::script('com_convertforms/conditional_fields.js', ['relative' => true]);
$options = JFactory::getDocument()->getScriptOptions('com_convertforms');
foreach ($conditions as $key => $form_1_condition)
{
    $parts = explode(':', $form_1_condition);

    $options['conditional_fields'][1][] = [
        'if' => [
            [
                'field_name' => $parts[0],
                'value' => $parts[1]
            ]
        ],
        'then' => [
            [
                'field_name' => $parts[2],
                'trigger' => 'show_field'
            ],
            [
                'field_name' => $parts[2],
                'trigger' => 'is_required'
            ]
        ],
        'else' => [
            [
                'field_name' => $parts[2],
                'trigger' => 'hide_field'
            ],
            [
                'field_name' => $parts[2],
                'trigger' => 'is_not_required'
            ]
        ]
    ];
}

JFactory::getDocument()->addScriptOptions('com_convertforms', $options);