As I know for now there is no any feature to do that in intellij idea. I dont know why but they dont support to do that, at least this is the result which I found with all my re
Projects in Eclipse are Modules in IntelliJ. I do not recommend using them the same way - ie importing unrelated projects as modules into one IntelliJ project.
Importing for example database project and application project into one is ok, or when working on one project means working on another. But when you import too many projects into one, you will have a problem with searching and "Go To File/Class" actions, and you will use too much heap space.
Generally, when you have a lot of opened projects, there are three problems
To solve this, I have made Frame Switcher plugin for easier switching between projects, and reopening closed ones. Also, when you have 32 bit Windows and have too many projects, then you need to start new IntelliJ instance, and Frame Switcher can integrate them.
There is also Missing Functionality plugin which lets you "Close All Other Projects".