Released @June 9, 2021, Notion have introduced a new block type called Synced Blocks. These blocks can be edited in a single location and will sync across all pages where that same block exists.
- Create the block you would like to sync everywhere. It can be as simple as a text block but you can add any sort of information inside it.
- Click to turn it into a synced block
- Once you have your synced block, copy the link and paste it anywhere else you wish. Any changes you make to the original will show up in all other page.
- The same goes for making changes the other way around. Any changes you make on another page will sync back to the original and update your content everywhere.
You could use a synced block to create a navigation menu across multiple pages. I use one for the menu on this site.