Sorry you are having problems with this. I've opened an internal case (86654) to track the request to set the parent for individual subnets (instead of needing to select 2). Until we can get a better fix for this here are a few tricks that might help out .We're also actively working on improved importing which would allow you to specify the parent group or supernet or group as part of the subnet import.
My mouse has a scroll wheel, I can select the subnet then scroll up and drop the subnet into the proper place. Make sure you expand your parent container before you do this so you can drop it in the right place.
You could also move all of your items (subnets, supernets, and groups) into a new temporary folder. This will free up enough space to drag and drop subnets into the right place.
I realize these aren't ideal, but hopefully it will get you through the organization process while we work to make this a more natural work flow.
Any update on this?
We are having the same issue while managing hundreds of Groups/Supernets/subnets.
We have created the groups and now must move the subnets into the correct groups.
You have to wiggle the mouse right below the column headings in the left panel. There's only a very small area where the window will start scrolling. Watch this video -> ipam-inteface - DanSmart's library
I would like to see the keyboard keys enabled for moving subnets. Up and down arrows move as expected. Page up and down to top or bottom of currently viewable items, or the next page of items up or down. Home/End to top or bottom of list.
An "expand all' and "collapse all" would also be helpful.