Hello, @Lasitha851,
Yes, You can create sub-menu items in static blocks I have recorded a video for you please watch it to understand better how you can make it: https://streamable.com/ei104l // To know how to add a static block in the menu item
https://streamable.com/mwwx3h // To know how to set menu items in static block
The layout you want is only possible if you create sub-menu items in static blocks so it is necessary to watch the video to understand.
Regards 8Themes Team.