Visual Composer Custom Element Settings. This settings will show when the element is used in the backend.

VC_MAP.php

/*
* Wp Bakery Page Builder custom Element Code
*/
/*
* vc element single post 2
*/
function fts_single_post_two_vc_callback(){
  vc_map( array(
    'name'        => __('Single Post 2','js_composer'),
    'description' => __('Single post section', 'js_composer'),
    'base'        => 'single_post_two',
    'category'    => __('Content','js_composer'),
    'params' => array(
      array(
        'type' => 'attach_image',
        'heading' => esc_attr__( 'Image', 'js_composer' ),
        'param_name' => 'post_image',
        'description' => esc_attr__( 'Upload Image.', 'js_composer' ),
      ),
      array(
        'type' => 'textfield',
        'heading' => esc_attr__( 'Height', 'js_composer' ),
        'param_name' => 'post_height',
        'description' => esc_attr__( 'Give the post section height.', 'js_composer' ),
      ),
      array(
        'type' => 'textfield',
        'heading' => esc_attr__( 'Button Text', 'js_composer' ),
        'param_name' => 'post_button_text',
        'description' => esc_attr__( 'Give the button text.', 'js_composer' ),
        'value' => esc_attr__('Read More','js_composer')
      ),
      array(
        'type' => 'dropdown',
        'heading' => __( 'Button size', 'js_composer' ),
        'value' => array(
          esc_attr__( 'Large', 'js_composer' ) => 'large',
          esc_attr__( 'Small', 'js_composer' ) => 'small',
        ),
        'param_name' => 'post_button_size',
        'description' => __( 'Select button size', 'js_composer' ),
      ),
      array(
        'type' => 'vc_link',
        'heading' => esc_attr__( 'Button Link', 'js_composer' ),
        'param_name' => 'post_button_link',
        'description' => esc_attr__( 'Change link of button.', 'js_composer' ),
      ),
      array(
        'type' => 'textfield',
        'heading' => esc_attr__( 'Category', 'js_composer' ),
        'param_name' => 'post_category',
        'description' => esc_attr__( 'Use comma(,) for multiple.', 'js_composer' ),
      ),
      array(
        'type' => 'textfield',
        'heading' => esc_attr__( 'Title', 'js_composer' ),
        'param_name' => 'post_title',
        'admin_label' => true,
      ),
      array(
        'type' => 'font_container',
        'param_name' => 'title_font_container',
        'value' => 'tag:h2|text_align:center',
        'settings' => array(
          'fields' => array(
            'tag' => 'h2',
            // default value h2
            'text_align' => 'center',
            'font_size',
            'line_height',
            'color',
            'tag_description' => __( 'Select element tag.', 'js_composer' ),
            'text_align_description' => __( 'Select text alignment.', 'js_composer' ),
            'font_size_description' => __( 'Enter font size in px e.g. 30px.', 'js_composer' ),
            'line_height_description' => __( 'Enter line height in px e.g. 35px.', 'js_composer' ),
            'color_description' => __( 'Select heading color.', 'js_composer' ),
          ),
        ),
      ),
      array(
        'type' => 'checkbox',
        'heading' => __( 'Use theme default font family?', 'js_composer' ),
        'param_name' => 'title_use_theme_fonts1',
        'value' => array( __( 'Yes', 'js_composer' ) => 'yes' ),
        'description' => __( 'Use font family from the theme.', 'js_composer' ),
      ),
      array(
        'type' => 'google_fonts',
        'param_name' => 'title_google_fonts',
        'value' => 'font_family:Abril%20Fatface%3Aregular|font_style:400%20regular%3A400%3Anormal',
        'settings' => array(
          'fields' => array(
            'font_family_description' => __( 'Select font family.', 'js_composer' ),
            'font_style_description' => __( 'Select font styling.', 'js_composer' ),
          ),
        ),
        'dependency' => array(
          'element' => 'title_use_theme_fonts1',
          'value_not_equal_to' => 'yes',
        ),
      ),
    ),
  ) );
}
add_action( 'vc_before_init', 'fts_single_post_two_vc_callback' );