Markers showing sub-sections in Menu

[ic360-com]

I think it would be helpful to add markers/icons showing which menu options have subsections within. Similar to how the menu works on this site https://www.gigant.co.uk/ (see the blue pullout menu on the left hand side).

I'm quite old school and still prefer to browse the Menu structure of Docs, so I know where things are... but it's not obvious which options have sub-sections, in the Menu. For example, I couldn't find the Branding information (login screen logo) but used the Search tool in the end.