Formal or written expression that marks a location, situation, or domain. Often used in academic or official contexts to mean 'in (a particular field/context)' or 'regarding'. Not used for physical location in casual speech.
The declining birthrate problem in Japan is serious.
Please let us hear your opinion regarding this point.
で is the everyday particle for location or means, whereas における is a formal, written expression used to mark a domain or context, common in academic or official writing.
における is the standard hiragana form used in everyday and written Japanese, while おける (its variant, from 於ける) reads more formal or literary but functions identically after a noun with に.
Compound of the particle に (locative/target marker) and the verb 於ける (archaic 'to be at'), now fossilized as a formal adnominal expression.