Rules regarding the selection of personnel shall be established as follows.

Literal

Personnel [attributive-の] selection [regarding-に関する] rules [object-を] as-follows-[次のように] set.

Legal/bureaucratic prose. ~に関する ('regarding, concerning') is the standard formal attributive for noun modification — 'the rules regarding X.' 定める ('to establish, to prescribe, to set') is the standard verb for enacting rules, laws, regulations, or constitutions. 次のように ('as follows') precedes a listing. This is the preamble style you see on Japanese legal documents.