I have vertex groups in my model that is bind with automatic weights to an Armature. I have another model with particle system with Vertex group_(Hairs). So, I want both Vertex groups - previous one_(with automatic weights) and one with_(particle system).
To copy the vertex group of an object that is exactly the same, give your object a Data Transfer modifier, Source > object with the hair vertex group, Mix Mode > Add, enable Vertex Data and Vertex Groups, Mapping >Topology, click on Generate Data Layer and apply the modifier. Now the object should have inherited the hair vertex group.