No. No matter how complex your symbol is, Illustrator sees the instance of a symbol as a single object, so it can only be on one layer. Expanding the symbol produces multiple objects, but they are groups and a group can only be on one layer. If you ungroup, you can reposition parts on different layers, but you would have to do this manually, because Illustrator forgets layer assignments within a group. You also can’t have a symbol automatically assigned to a specific layer.
You might be able to script this. A simple script could move all symbols starting with “A” to Layer A, all symbols starting with “B” to layer B, and so on. A more complex script could expand and ungroup a symbol, then assign layers based on the names of the objects within the symbol. To do this you would use the Layers panel to name all parts of the artwork before making a symbol. I know nothing about scripting, so I don’t even know if these actions are possible. Sounds like a hell of a lot of work, especially that second option.
Unfortunately, this is what I expected. Thanks for the feedback.
I think it is an excellent feature request I can see where this would be helpful.
I won't want it easily edited but would like it to be available in isolation mode.
For workarounds, you need to explain the "system" more fully.
Example: Is the "system" such that Instances reside in the same place in all the renderings (i.e.; the problem can be boiled down to a simple matter of replacing existing Instances with Instances of other Symbols)?
Are you talking about always the same number of instances on a given layer?
Do the positions of the Instances change for different renderings?
How many different Symbols are we talking about being associated with a particular Layer?
Are you aware of the Paste Remembers Layers command? Instead of several "palettes" (are you talking about having several Symbol Libraries open?), have you considered using Templates with the Symbol Instances already on a page instead of Libraries? That would let you simply copy the Instances you want to use in a new rendering, switch to the rendering document and Paste. The Instances would then Paste onto the Layers from which they were copied.
Are you aware of the Replace Symbols command?
Have you considered whether Variables and DataSets might work better for this than Symbols?
The more fully you explain the parameters of the project, the more likely you will receive practical workarounds.
I'll elaborate on our current system a bit more.
1. Instances do not reside in the same place on all the renderings. We have roughly 120 illustrator templates set up, most of which are similar but all vary per rendering as each represents a different product.
2. There are not always the same number of instances on a given layer.
3. The position of the instances changes on virtually every rendering.
4. The number of symbols that would be associated with a particular layer varies depending on how much of that particular product line a client is interested in. Anywhere from 1 on the low end to possibly 50 or so on the high end.
5. I am aware of the paste remembers layers function. Due to the complexity of our expansive component based system, I'd guess we currently have atleast 500+ symbols set up over a couple dozen palettes (set up as symbol libraries). Additionally each component has its identifying part# displayed next to it so that our clients/production team can identify them by looking at the rendering. Not only that, but some of these components are very small. Having all these symbols already on the page, or even on several pages just isnt realistic due to the scale and volume.
6. Replace symbols isnt really an option as we are constantly bringing in/adding symbols based on our expansive component-based system.
7. I haven't delved very deep into variables and datasets in Illustrator, so I'll try to take some time and explore them to see if there are any viable options there.
Thanks again for the feedback. I appreciate it.