Different attacks made with such a weapon can be made using different profiles if you wish.
If the selected weapon has more than one profile that you must choose between, you must declare which profile is being used at the same time.
If a model has more than one melee weapon and can make several attacks, it can split them between these weapons however you wish – declare which attacks are being made with which weapons before any attacks are resolved. If a model has more than one melee weapon, select which it will use before resolving any attacks.