Seating section (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">seating section</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for tier that I've seen before include "he hasn't won?" , "one doing Bond" , "He might do sailor's knots" , "Rite about layer" , "Rite for a rank" .)