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

https://bizzmarkblog.com/what-anchor-text-should-i-use-for-tier-2-links-pointing-to-tier-1/

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 your Tier 1 links by linking to them, which helps strengthen their impact