There is no such thing as a Job Seekers visa. You may be confusing it with the working holiday visa or visitor visa – which give you the opportunity to look for jobs in HK. This is a permitted activity.
On a visitor visa you can not actually take up any employment that results from your search process. While on a working holiday visa you are allowed to take up employment in Hong Kong within a limited period of time, during which you will be allowed to work for different employers for a period on three months each.
But there is no special Job Seeker’s Visa in Hong Kong.