Both Hazelnut Paste and Hazelnut Butter are made from the same ingredients using a mix of hazel nuts and sugar syrup.
So that makes the Hazelnut Paste and Hazelnut Butter the same thing however hazelnut paste and hazelnut butter have a slightly different taste from each other.
When making hazelnut paste the hazelnuts are roasted in caramel before they are processed and turned into paste so that makes the hazelnut paste sweeter tasting than hazelnut butter.
Hazelnut Butter does not go through the roasting process in caramel before being processed into the hazelnut butter.
The only difference you'll notice between the hazelnut paste and the hazelnut butter when making recipes is the taste.
But essentially hazelnut butter and hazelnut paste are the same thing using the same ingredients.