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

https://www.golf-bookmarks.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 ranking. Tier 1 links point directly to your site and carry the most value. Tier 2 links support those Tier 1 links, making them stronger and more effective