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

https://wiki-byte.win/index.php/Should_I_Build_Tier_2_Links_to_Guest_Posts_or_to_the_Homepage%3F

Tiered link building uses two levels of links to boost your site’s authority. Tier 1 links point directly to your pages and carry the most weight. Tier 2 links support Tier 1 by linking to those pages, strengthening their impact