They used CEV ranking in the past with host as no. 1. So we have to wait for host confirmation. I think that at this point only Turkey and Luxembourg are interested in it so the groups can be like this:
I: NED/TUR, BUL, POL, AZE
II: NED/TUR, GER, BEL, CRO
Basically Turkey can choose in which group they will be. If they will organize in Pool I and if not in Pool II.