Maven sibling module support

Hi, I have a maven project which has a structure in file system like this

+-- project_parent
|        +-- pom.xml
+-- project_moduleA
|        +-- pom.xml
+-- project_moduleB
|        +-- pom.xml

pom.xml in project_parent directory defines the sibling relationship between module A & B.

<!-- pom.xml in project_parent -->
<project xmlns="" xmlns:xsi=""
    <description>Parent Module of the Project</description>

Also, module A imports module B as a dependency in pom.xml.

I am managing module A and B separately on GitHub and using Circle CI as the CI service for each one. Since they are treated as different project, when CI test ran in module A, “Could not resolve dependencies for project” error would appear.
I tried to add module B as a git submodule for module A but didn’t help.

Could anyone kindly tell me how can I achieve maven test in Circle CI for module A?