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

https://wiki-fusion.win/index.php/What_Is_Tiered_Link_Building_in_SEO_and_Is_It_Safe%3F

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