Hi. No, not yet, but this is on our list. I’ll review this feature with our product team, but we have a quite a few higher priority stories for more core features that are taking development time ahead of this.
One way to make symbols organized is to namespace the symbols. So when you see some of the symbols libraries we’ve created on Mockups to Go, you may see a prefix like for Bootstrap, we’ve used a pattern like “bs_[control/component”, e.g. bs_button. That way in quick add, that prefix can be used to filter. Ideally, we also provide a visual way to filter in the UI Library, and that’s what we’re planning.
If others would like to see this feature, please let us know (or add your Like/Heart vote above) to help us prioritize this request.