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

https://www.oscarbookmarks.win/learn-how-tiered-link-building-boosts-your-website-s-authority-step-by-step

Tiered link building uses two levels of backlinks to boost your site’s authority. Tier 1 links point directly to your site and are high quality. Tier 2 links support Tier 1 by linking to those backlinks, helping them carry more weight