Is there a way to separate foliage actors?

I’ve merged one level into another. Upon doing so, the foliage actors from both levels have combined. The problem is that I would like to move all of the foliage actors from the level (Level 1) that I merged into the other level (Level 2) without moving the foliage actors from Level 2, but the fact that they are all grouped together seems to make it impossible to do so.