How to run docker container in parallel with isolation

I want to run the multiple chrome and multiple test script in isolation

docker-compose.yml

version: "3"
services:
  chrome:
    image: selenium/standalone-chrome-debug
    privileged: true
  webtest:
    build: .
    links:
      - chrome

When I run

docker-compose scale chrome=5 webtest=5

Then it’s starting the multiple chrome and multiple webtest. But some of my webtest is sharing the chrome. How can I scale docker container to run in the isolation (Not to share the chrome)

Source: StackOverflow