The Join Projects node, listed under the Analysis tab lists all join projects in the current repository. If there are no join projects defined yet, or you need to create a new project, you can create it from the Join Projects node.
For instructions, see Creating a Join Project.
Within the Join Projects node, there are two sub-folders: Entities and Processes. The Entities folder lists all source and join entities within a join project. Join entities are a result of a join process and can be treated as dynamic entities except for they can be immediately used as inputs to a join process. The Processes folder lists all joins within a join project.
Each join process further contains the Inputs and Outputs folders which lists the input entities and output entities respectively.
In the icon view, a join project looks similar to a simple join.