How to use assembly (y/n)relations (for sub asm. parts and features)?

[designtrans]

Could any one let me know, How to use yes_no, string relation from top level assembly to below sub assembly and parts, feature to suppress/resume. I know it for pro/program...n I know individually how to apply for parts or features but I want to drive from top level assembly (like dimension relations).......I get it done by some other way but I want exact way to apply.