The word "tier" refers to a level or category that ranks something based on a specific criteria. It helps to separate or group things according to their importance, quality, or position. Full definition
Though, in the ongoing season, they are in 2nd position on the EPL point table but still they are 15 points behind than the top tier of point table. (tsmplug.com)
Even at the top tier of bonus category earning it only earns 3.5 X on dining and travel and 2.6 X on everything else. (uponarriving.com)
The entire season of fall demonstrated the same disparity between daily maximum and minimum temperatures, but with the pattern shifted so that the southern tier of BC experienced the record daily minimums. (pacificclimate.org)