Selecting entire groups when creating connect board

Hey,
Since Monday doesn’t allow you to create groups within groups in order to show a summary of each group, I tried to overcome the problem by creating a separate dashboard that would show the project at a “high level” as well as lower levels.
For this I used connected board and mirror columns. But the other problem I encountered is that when connecting the boards I can only select an item.
It doesn’t make sense that in a big project I would have to mark the items one by one.
I have already seen in previous posts that this is a repeated request, but מothing has changed since then.
This is a link to the requests:

Can you add an option to select an entire group and also the entire project-this is a necessary functionality…

Thanks!