Problem
You want to change the default DevHub org in your sfdx configuration.
% sfdx force:org:list
=== Orgs
ALIAS USERNAME ORG ID CONNECTED STATUS
─── ─────────────────── ─────────────────────────────── ────────────────── ────────────────
DevHub1 devhub1@************.com AAAAAAAAAAAAAAAAA1 Connected
DevHub2 devhub2@************.com AAAAAAAAAAAAAAAAA2 Connected
(D) DevHub3 devhub3@************.com AAAAAAAAAAAAAAAAA3 Connected