The planBIM Revit plugin enables you to seamlessly navigate your way through different workspaces that you're a part of while you're inside the plugin.
Know more about workspaces in here.
To help you out, here are the steps of how you can switch between workspaces.
Click on the Profile button on the screen, as shown in the image below.
Next, in the plugin dockable, click on the Switch Workspace button.
The next screen will show the name of your current workspace along with a list of other workspaces that you're a part of. Click on the Switch button for the workspace of your choice.
You'll be redirected to the projects page where you'll see a list of the projects of the selected workspace in which you're an editor or manager.
If you scroll down in your profile in plugin you would see an option of creating a workspace,
Click on CREATE A NEW WORKSPACE as shown to create a new workspace and you would be directed to a new web page.
If you're working with a Revit file that is linked to a particular project of a workspace, and you switch to a different one, you won't be able to access the project modules till you either switch back to the earlier workspace or link your file with a different project in the new workspace.