In ProStructures CONNECT Edition, it is only possible to have one dgn file open. The program can be started again and another dgn can be opened in this session but there are also some possibilities to switch between the models.
1. Model browser:
The Model dialog shows all the models and sheets in the current drawing. Double click on required model or sheet will open them.
2. View Groups:
This tool box is usually displayed at the lower left side of the screen.
The flyout shows similar to the models dialog the models and sheets in the current file.
With the green arrow buttons it is possible to swap between models that have already been open in the running session.