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

https://wiki-spirit.win/index.php/What_Does_%E2%80%98Natural_Link_Growth%E2%80%99_Look_Like_for_a_Tiered_Campaign%3F

Tiered link building uses two levels of links to boost your site’s rankings. Tier 1 links point directly to your main pages, driving real traffic and authority. Tier 2 links support those Tier 1 links, making them stronger and more effective