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

https://www.bookmarking-planet.win/this-article-breaks-down-tiered-link-building-in-simple-terms-it-explains-how

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 those Tier 1 pages, helping them rank higher