How to Use Nested Blocks in Shopify Horizon Theme

Horizon is built on Shopify's newer theme block system, where blocks can contain other blocks — this is the single biggest editor difference from older themes like Dawn.

Steps

1. In your Shopify admin, go to Online Store > Themes and click Customize on Horizon.
2. Select any section and look at its block list — some blocks show their own Add block option nested inside them, rather than only at the section level.
3. A slideshow is the clearest example: the slideshow section holds slide blocks, and each individual slide block can hold its own text, image, or button blocks arranged however you like — not a fixed template per slide.
4. Rearrange nested blocks the same way as top-level ones: drag them in the left-hand list, or use the up/down arrows.
5. Anything locked by the theme (like navigation controls on a slideshow) stays fixed even as you customize what's nested inside it.

Why this matters

Older themes let you customize a block's settings but not its structure — you got one layout per block type. Nested blocks let you build a genuinely different layout inside the same block, which is why Horizon's sections can look far more varied store to store than Dawn's.