Yeah that is possible as I have it like that I have the same item in (food colouring) & its also in my (seasonal Christmas) category.
When you go into an item specifics like where you add price etc or description scroll right down to the bottom where it has select categories.
The click to select your categories in there you can select to have that product show in (candles) & (pick & Mix) if you have those 2 categories set up.
