By default each spectrum has one peak list associated with it. But you can add extra (empty) ones, duplicate (clone) peak lists or read in a peak list from another programme (using the Format Converter). Only one peak list is active it any one time, so if you are working with several peak lists, then make sure the correct one is active. Under Current Peak Lists in the Crosspeaks menu you can see and manage all your peak lists.
To actually look at a particular list and the peaks within it, go to Edit Peak Lists in the Crosspeaks menu. A useful feature within this pop-up is the ability to choose a window from the top right hand drop-down menu and then go to Find Peak. That window will then centre on the selected peak and be marked with a thick black mark.