Currently, there is not an automated way to combine files. What you can do is copy and paste any of the objects (data or commands).
To move data between files,
- Click one of the column objects.
- Command-A to select all.
- Command-C to copy.
- Go to the file you want to paste them in.
- Command-V to paste.
For a single graph with commands, you would do the same steps, but start by clicking on one of the commands in the graph do you want to copy. You can also copy and paste the Layout settings. That said sometimes the data connections may not work properly when going between Files when you have data nested in group.
So not sure if this completely helps you. Maybe you could let us know a little more about what you need to combine.