Apple Motion Particle emitter within a group not animating with the group

Particles don't animate with the Emitter (or an animated parent group) once they're "born". They're animated by the Cell Controls at the point of their birth. Depending on your Emitter (and cell controls settings) you may not be able to tell the difference.

The crosshair is the position of the Emitter animated at both the Group level and the Emitter itself [Birth Rate set to 5]. For the first half, there is no cell animation — Life is set for the length of the project (10). After the halfway point, Speed is set (keyframed) to 100 and Life down to 1. Notice that it doesn't affect those particles born before the changes.

HTH

If you're still having issues (and I expect so), you can rotoscope/mask out the building and use it as a source image for the Emitter [Set the Shape parameter of the emitter to Image, then the Arrangement to Outline, drop the masked building layer into the Image Source.] This Emitter setup ***should*** follow the building outline through the scaling/zoom without the Clone.

Duplicate the building image to keep all the background — mask the copy.

I made a short test with an emitter inside a group, and a "Motion Path" behavior applied to the group.

The emitter DID move with the rest of the group.

It is possible that there is some conflict between the animation applied to the emitter and that of the group.

Would it be possible to share a minimal example showing the problem?

Try taking off the zoom/scale of the "scene". Make a Clone of the Group, then add the zoom animation to the Clone. (Turn off the original group.)