Compare Items

In product setting:

Result:

Choosing the metafield (version 1.3.0)

The Compare products section reads this content through its Compare items metafield setting. The default key is custom.compare_items.

Keep the default key above and it works with no extra setup.
Or rename it: create the metafield under your own namespace.key (for example, your brand name), then set Compare items metafield to match.
Reuse on one page: create one metafield per copy (for example custom.compare_items and custom.compare_items_2) and point each Compare items metafield at its own key to show different content.