Getting right object of group

How do I...?
#1

I want to add tail to rockets in my game because some of them are dark and besides it look cool. So I decided to use particle system.

The “Bullet” (hasn’t decided if it’ll be bullet or actual rocket) and tail are in one object group. Positioning “tail” direction of particles against bullet/rocket movement shouldn’t be hard.
Unfortunately though I don’t know how to pick right objects so bullet and tail would be in same group instance (so I don’t get funky result like tail positioning against rocket that is flying in opposite direction). How to do that?

#2

Groups are not meant to be used for these purpose and won’t be of a great help.

Instead, take a look to the “Linked objects” extension. When creating a rocket, and its tail, use the extension to link (virtually) the objects together.
Then, if you’re for example iterating over all rockets ( using a for each event ), you can use the appropriate action to get the associated tail object.