expression
as far as ... is concerned; so far as ... can tell
Used to limit a statement to a particular topic or perspective. Follows a noun or noun phrase.
See also: 関する
私に関する限り、その計画に反対です。
As far as I'm concerned, I'm against the plan.
天気に関する限り、明日は大丈夫そうだ。
As far as the weather is concerned, tomorrow looks fine.
関する is a verb meaning 'to concern' or 'to be related to'; に関する限り is a fixed expression built from it.
Combination of に (particle), 関する (verb 'to concern'), and 限り (noun 'limit'). Literally 'as far as it concerns'.