General project we recommand using the single module mode, it project is complicated, multi-layer controller can be used to divided controoler by feature. If still it can't meet your requirements, try create multi-module project.
--mode=module to create a molti-module project.
thinkjs new demo --mode=module
There are differences between single-module and multi-module project in project structure:
src/common to store common code
src/home default module
src/xxx modules added according to feature