You only have to enter your expenses in one spot.
"Expenses which you incurred for the entire home" is where you would put things like rent, property tax, utilities, etc... that you can only claim a portion of based on how much of your home you use for work.
"Expenses which you incurred for office space only (not for entire home)" is for expenses that you just use for work, so you can claim the full amount. For example, if you have an internet connection just for work, then you can enter it here.
