I think your  tring to load an inject not a pose. Go to Pose > !Daz's Victoria 3 > V3 Fashion 01 and load that in both sides. Then load L3 in left side and V3 i right side. You should now see that you have all your goups showing doubled.

Right Click and copy all morphs of all the groups, except the body.

Body needs to be copied differently, this will give all your PBM's. Copy all channels except the (trans,scale offsets and rots. You can delet these first and then use copy all to save time.)

That's it. Pretty simple.