How to use Product group?

I’m new to InvoicePlane, and I like it.
What is the purpose of a Product Group ? As far as I can see, neither offer nor invoice has a possibility to limit a product-search to some product group, which is what I would like.

The purpose of the product groups was to enable product grouping right from the release of the feature.
There may be further integration in other parts of the app in the future.