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

https://www.slideserve.com/richard_russell21/what-should-i-use-for-tier-1-links-if-i-want-to-rank-a-landing-page

Tiered link building uses two levels of backlinks to boost your website’s ranking. Tier 1 links point directly to your site for strong authority. Tier 2 links support Tier 1 by linking to those pages, making the whole structure more powerful