I am new to Quicken subscription, converted to Mac Classic Deluxe. I inadvertently hit a wrong key and placed my Stock Account in a Investment Group. How do I undo that and eliminate the group
Accounts are automatically grouped by type in Quicken Mac and the groups are not under your control. You can rearrange the accounts within a group but you can't move accounts to a different group, nor can you create or delete groups.
The Investing main group you see in the left sidebar automatically separates accounts into subgroups of "Brokerage", "Retirement", and "Education" based on the Type you select in the Account Settings screen. As @Jon said, there is no way to change groups or subgroups, although that is a long-requested feature which might appear sometime in the future. I'd like to be able to have two separate sub-groups under Retirement in order to separate my traditional and Roth retirement accounts, but there's no way to do that, either.