Create a simple project with pom.xml only. Add your dependency and run:
Unfortunately dependency mojo must use pom.xml or you get following error:
Cannot execute mojo: tree. It requires a project with an existing pom.xml, but the build is not using one.
2) Find pom.xml of your artifact in maven central repository
Dependencies are described In pom.xml of your artifact. Find it using maven infrastructure.
Go to http://search.maven.org/ and enter your groupId and artifactId.
Or you can go to http://repo1.maven.org/maven2/ and navigate first using plugins groupId, later using artifactId and finally using its version.
For example see org.springframework:spring-core
3) Use maven dependency plugin against your artifact
Part of dependency artifact is a pom.xml. That specifies it's dependency. And you can execute mvn dependency:tree on this pom.