[合「あ」]う => To do A together/mutually N4
Secondary Verb
その[結果「けっか」] => Because of A (in the past), B N3
Reason, Result, Response
[要「よう」]するに => A. In short/put simply, B N2
Adjectival, Descriptions
[必要「ひつよう」]はない => It is not necessary for A to be done N2
Needs, Requirements