You’ll have to add your own customizer controls to achieve that.
So for example, if you want to add Company Name, you can use this code:
function my_register_additional_customizer_settings( $wp_customize ) {
$wp_customize->add_setting(
'my_company_name',
array(
'default' => '',
'type' => 'option', // you can also use 'theme_mod'
'capability' => 'edit_theme_options'
),
);
$wp_customize->add_control( new WP_Customize_Control(
$wp_customize,
'my_company_name',
array(
'label' => __( 'Company name', 'textdomain' ),
'description' => __( 'Description for your field', 'textdomain' ),
'settings' => 'my_company_name',
'priority' => 10,
'section' => 'title_tagline',
'type' => 'text',
)
) );
}
add_action( 'customize_register', 'my_register_additional_customizer_settings' );
PS. Here you can find more docs regarding this topic: Theme Customization API