What are natural remedies to prevent waking up multiple times per night?

Address why waking. This is a very complicated quesiton to answer. You need to figure out what the wakings are about. Can be as simple as stress or anxiety about an issue or can be your body telling you it is in trouble (as in the case of osa). If it is affecting your daytime function, seek professional help to make sure it is not a sleep disorder that needs treatment. As your primary care if you are not sure.
Several. A thorough assessment is the first step.The reasons for poor interrupted sleep are many, some serious.The treatment depends on what is causing the problem.You would not treat sleep apnea with herbs or pills.There are several "natural " treatments commonly used, ie chamomille, valerian, melatonin, tryptophan, lemon balm, lavender, neurofeedback, meditation, and good sleep hygiene.
Natural soporifics. Chamomile , valerian root, have been used, however, you first need to know why you are having insomnia. There are many causes. Symptomatic treatment won't get to the source of your sleep disturbance . After evaluation and diagnosis, natural remedies for sleep may afford you less risk than traditional pharmaceutical sleep meds, which have some disturbing risks long term according to some mds.