Selecting a Property within a Property (and so on)

I know how to select a "top" level property using scripting such as "position" or "opacity."

app.project.activeItem.selectedLayers[0].selectedProperties[0];

But how do I dig deeper into properties?

For example, to access the "X Rotation" of the Particle Replicator inside of Element 3D you need to follow this track:

Element 3D > Group 1 > Particle Replicator > Rotation > X Rotation

Is there a way to iteratively dig deeper into the property of a propterty of a proptery... ? My final goal is to apply a specific expression to the currently selected property no matter how deep it is.