Assemble Task in VR

Hello everybody,

I am trying to create a VR scene in which the player should assemble a component building with different pieces, according to instructions.

I am using the SnapInteractor/SnapInteractable logic, but once I have assembled the first two pieces I want to make them work like they are one piece.
I want to grab them by one piece or another, dividing them only using two hands.
At the moment, if I grab the Interactable piece they work like one, if I grab the Interactor piece it separates itself from the Interactable.

Does it exist something to use for this purpose?