Auto group selection for HDA

[roh.mizuno 0]

Hi, I am having trouble having my custom HDA group selection to behave the same way as existing nodes to work with group selections. For exemple, if I select certain edges of my object and create the node "Normal", it will automatically assign those edges to the node group, however, If I do the same with a HDA the result is not the same. 

I can add the "selectGroupParm" script to the group action button so I can create the group after the node creation, but I was wondering what extra steps I need to make in order to make it automatic when summoning the HDA.

 

Thanks!!