Custom the job submit form

Hi All,

I tried to remove the unnecessary fields in the job submit form. I put the following codes in the theme/functions.php

function custom_submit_job_form_fields( $fields ) {
	unset($fields['company']['company_twitter']);
	unset($fields['company']['company_logo']);

    return $fields;
}
add_filter( 'submit_job_form_fields', 'custom_submit_job_form_fields' );

It works fine. However, there are some fields I can’t find their name (field name) in the class-wp-job-manager-form-submit-job which are

GOOGLE+ USERNAME (OPTIONAL), FACEBOOK USERNAME (OPTIONAL), LINKEDIN USERNAME (OPTIONAL)

Do anyone know how to remove these three fields?

Thanks,
Jacky

https://wordpress.org/plugins/wp-job-manager/