Some feedback and observations are as follows:
1. Allow user to type a tag for the group, e.g:
"e*x regs" =$e*x
This tag will be some mnemonic the user understands, and will be helpful to quickly remember what the _expression_ group contains. A tag is useful because the user might group together arbitrary expressions relevant in a particular debugging scenario and then tag the debug scenario.
2. On right click popup of a child _expression_ (inside an _expression_ group), disable popup menuitem "Remove" on a child _expression_. This removes the entire group, not the selected child _expression_.
3. When the node "Add new _expression_" goes into edit mode, open an infopop which advertises this _expression_ grouping feature.
4. On rightclick popup menu of an _expression_, show menuitem "Add to _expression_ Group". This will open a list dialog which lists all existing _expression_ groups + "New". If user selects an existing _expression_ group, edit the group definition string to append "; <_expression_>". If user selects "New", add a new _expression_ group with the definition "<_expression_>;".
5. Allow user to drag / drop an _expression_ on a group.
6. To edit an _expression_ group defintion which contains multiple complex expressions, it is actually easier to rightclick the group and open Edit Watch _expression_ dialog. Here, it would be great if user can specify expressions one per line, each _expression_ ending in semicolon. If a line ends with semicolon, we should discard the newline char after it and create a single line for the _expression_ group definition.
