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

https://www.easybookmarkings.win/tiered-link-building-helps-boost-your-website-s-authority-by-layering-links

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