Question about arranging menu bar

can the menu bar be adjusted and rearranged?
eg: group extensions

Menu bar are toolbar? The menus cannot be rearranged. You can arrange toolbars and place them wherever you wish.

This depends on the extension developer and how they organise things.
There are some UserInterface suggestions available for them, but they still have to implement it.
In SketchUp 2022, you can use the searchbar (Ctrl + F) and start typing what you need.