Tiered link building uses two levels of backlinks to boost your site’s...

https://eduardossmartcolumn.cavandoragh.org/broken-link-building-step-by-step-using-ahrefs

Tiered link building uses two levels of backlinks to boost your site’s authority. Tier 1 links point directly to your site and carry the most value. Tier 2 links support Tier 1 by linking to those pages, making them stronger