N2 — outside your level filter
amid — a formal preamble naming a state the main clause proceeds within or despite
本日はお忙しい中をご出席いただき、誠にありがとうございます。
honjitsu wa o isogashii naka o go shusseki itadaki, makoto ni arigatou gozaimasu.
Thank you very much for attending today despite your busy schedule. formal
雨の降る中を、傘も差さずに歩いて帰った。
ame no furu naka o, kasa mo sasazu ni aruite kaetta.
I walked all the way home through the pouring rain without even an umbrella. neutral
Variants
中nakaalternant
bare 中 is the register-neutral default (お忙しい中、ご出席いただき); を adds a "pushed through it" traversal flavour and wants a motion-ish main predicate, not the reverse.
中を
なかをnaka oN2formal