To be on top of a hill in dreams indicates you are aware of your own expanded vision. You have worked hard to achieve something and are able to survey and assess the results of what you have done.
To be climbing a hill in the company of others in dreams often indicates that you have a common goal – that a journey you thought was yours alone is actually not – and you can use their knowledge to help you.
To dream that you are going downhill would indicate you are feeling as if circumstances are pushing you in a certain direction.
If you are dreaming of an uphill struggle this could reflect your feelings in waking life, making you consider if the task is worth the effort to get to the top or if you’re undertaking a Sisyphean talk that’s taking you nowhere, pointlessly.