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

https://www.ready-bookmarks.win/tiered-link-building-scales-authority-without-wasting-budget-by-pointing

Tiered link building uses two levels of backlinks to boost your site's authority. Tier 1 links point directly to your site, giving it real value. Tier 2 links support those Tier 1 links, making them stronger and more effective