[Domain Mapping] NBT Gravity Form integration hook to show specific template is not working

At this thread you guys gave a code to show just a specific template at a chosen Gravity Forms form: https://premium.wpmudev.org/forums/topic/select-a-specific-new-blog-template-using-gravity-forms#post-1206937
However, it is not really working. It just shows the templates instead the checkbox input field, but nothing happens if I chose a specific template there. But I don`t want just a specific template either. I would like, actually, to be able to choose a specific template category to bring its templates attached at my chosen form. Below is the given thread hook code. What should I change in it in order to get that?

<?php

add_filter( 'gform_userregistration_feed_settings_fields', function( $settings ) {
	if ( ! function_exists( 'nbt_get_model' ) )
		return $settings;

	$model = nbt_get_model();
	$templates = $model->get_templates();
	$choices = array(
		array(
			'label' => 'Select template',
			'value' => 0
		)
	);
	foreach ( $templates as $template_id => $template ) {
		$choices[] = array(
			'label' => esc_html( $template['name'] ),
			'value' => $template['ID']
		);
	}

	$settings['nbt'] = array(
		'title' => __( 'New Blog Templates', 'blog_templates' ),
		'description' => '',
		'dependency' => array(),
		'fields' => array(
			array(
				'name' => 'gf_user_registration_multisite_blog_templates_template_id',
				'label' => __( 'Template', 'blog_templates' ),
				'type' => 'select',
				'choices' => $choices
			)
		)
	);
	return $settings;
}, 50);

add_filter( 'gform_submit_button', 'nbt_hooks_render_hidden_form_field', 15, 2 );
function nbt_hooks_render_hidden_form_field( $button_input, $form ) {
	$user_registration = gf_user_registration();
	$config = $user_registration->get_feed( $form['id'] );
	$template_id = absint( rgar( $config['meta'], 'gf_user_registration_multisite_blog_templates_template_id' ) );

	if ( $template_id ) {

		if ( ! function_exists( 'nbt_get_model' ) )
			return $button_input;

		$model = nbt_get_model();

		if ( ! $model->get_template( $template_id ) )
			return $button_input;

		$button_input .= ' <input type="hidden" class="gform_hidden" name="blog_template" value="' . $template_id . '" />';

	}

	return $button_input;
}

Thank you very much! :wink: