Nested Tag In Enfold Theme Element

You will want to separate your triggers from your targets. This can be done using the roll-your-own method. Since you mentioned nested elements, it sounds like you will either have multiple triggers or multiple targets. Multiple triggers are fully supported by collapse-o-matic, however multiple targets are a more advanced feature that is only available with collapse-pro-matic.

While Collapse-Pro-Matic is not free, it does comes with a very high level of personal support, including setting up a working demo directly on your site, so you have a clear path to get things setup and working in short order.