Yes, by using the automatic sorting function. When you're at a location that is not a store, the categories will be sorted alphabetically. It that's not happening see this post.
When you enter a location where many purchases have taken place, the app will show a sort button top right (arrows up and down). Tap this to show a store selection screen - find the store you're in on the list and tap it. The store name is now shown in the app header. Grosh now analyses the sequence you and all other users are swiping items - and generates a sorting of the list based on this. It gets better over time and also gradually takes into account that some items are being moved around  in the store.
Manual sorting is not possible - if you believe there's a problem sorting the list in a particular store, please let our support know this (via the Send Message / Chat button).