Recently I was in the situation to debug couple of components that is not in the same pom.xml and It is not possible to open up different windows and debug!!
After view minutes of search in google, i found out couple of cool techniques, that allow us to debug different component in the same place. Lets go though it, step by step (here i will refer Idea intellij as IDE).
You can see the "Project Structure" button that appear in right hand side (Circled) of your current opened project.
You can see a "Modules" in left hand side in project structure. once you clicked that, you can see there is a "Sources" tab under the Name of the project.
Once you get into there, you can see a button named with "Add Content Root"
Then you have to select content root directory that you want to add into current project structure.
Finally you can see, you have add a content in to your project structure. If you want to add more content, repeat the Step 2 and Step 3.
Click Ok, you can see the changes in project structure with new content in it!
Now you can do you normal way of debugging your projects!!