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.