I am not entirely sure if you are asking about the difference between come and go or up and down but I'll try to help anyway. :)

We use:

go- for a movement away from us.

come- for a momement towards us.

up- for a upwards movement (such as up an incline like a hill or mountain) and often for movements north.

down- for a downwards movement (such as down a hill or mountain) and often for movements south.

So, 

If you are at the top of a hill  and you want to return to the bottom you might: go back down.

If you are at the bottom of a hill and you'd like to be on top you will: go back up.

If you are at the top of a hill and you'd like a friend to return, you might ask him or her to: come back up.

If you are at the bottom of a hill and you'd like a friend who is at the top to join you, you might ask him or her to: come back down.

P.S. 'back' here will show the return to a previous place.

I hope this helps.