Bash function that goes up X directories. (for in your ~/.bashrc)

up.sh

up(){
  local d=""
  limit=$1
  for ((i=1 ; i <= limit ; i++))
    do
      d=$d/..
    done
  d=$(echo $d | sed 's/^\///')
  if [ -z "$d" ]; then
    d=..
  fi
  cd $d
}