Hi Peter, there isn't exactly a grouping feature in MoI as of yet although there is a kind of related thing which is object names.

If you select a bunch of objects and assign them all the same name (click on the name line in the object properties panel in the upper right corner of the main window), then they will be kind of grouped together in that there will be a single name entry for them under the Scene Browser's "Objects" section and you can then use the controls on the scene browser to work on all those objects with one click like hide/show them or select them all at once, etc...

There isn't a way to make them all get selected when you just click on one of them inside the modeling window though, that kind of grouping is something that I definitely want to add in the future but it is not in there as of yet.

- Michael