概要

背景

Rails ERD - Configuration
抜粋

Rails ERD has the ability to be configured via the command line or through the use of a YAML file with configuration options set. It will look for this file first at ~/.erdconfig and then ./.erdconfig (which will override any settings in ~/.erdconfig). The format of the file is as follows (shown here with the default settings used if no .erdconfig is found). More information on customization options can be found in Rails ERD's project documentation.
railsアプリのリポジトリルートに.erdconfigを配置(~/.erdconfigでもいいけど、こんな使い方する人はいなそう）

以下のような内容を記述

only:
  - Product
  - Order
  - Customer

以下のようにコマンドを実行

bin/bundle exec erd --only="Product,Order,Customer"