Gitlab CI + maven: use another repo as a local dependency

Question

I started using gitlab for CI with maven. I would like to use another gitlab repo as a dependency for my project, but I don't know how to do this.

My current .gitlab-ci.yml:

image: maven:3-jdk-8
variables:
   MAVEN_OPTS: -Dmaven.repo.local=${CI_PROJECT_DIR}/.m2

build:
  script: "mvn clean install"
  artifacts:
    name: "oslib"
    paths:
    - "target/*.jar"