Knowledge is taking texts and files that match a keyword, doing further analysis, and discovering the truths hidden within.
Literal
Keyword [to-に] match sentences [and-や] files [from-から], further advanced analysis [obj-を] do-[and-して], hidden truth [obj-を] discover [nominalizer-こと] [subject-が] knowledge is.
A definition sentence in a corporate/IT register, probably from marketing copy. The pattern '[verb]ことが[noun]です' defines a concept by its activity — '[doing X] is [noun].' 合致する ('to match, conform') is formal vocabulary — in casual speech 合う would do. ナレッジ is a direct English loan used as buzzword; native equivalents exist (知識), but the katakana form signals 'corporate-speak.' 隠れている is the state-resulting ~ている on 隠れる ('to hide').