Trying to find a pass I can take from beijing to Hong Kong but that I can take stops along the way

If I buy a pass can I use it more than once? Say can I get off in Hunan and stay at a hotel for a night to explore the area; can I get back on the ride and continue on to Hong Kong the next day with my pass? Or is there a rail where you can buy a pass for a certain amount and use it unlimited amount of times?? Any help would be great! Planning trips are very stressful ha!