Angular Reactive forms 4 level saving data in Sql server

Question

I have requirement like this ..

Course then lesson then lecture then lecture type

---course parameters

country -- from db ( multi select ) name , title description -- html-- few more parameters

save cancel buttons ------

add lesson button ------------- edit lesson button remove lesson button

lesson parameters - lesson name

lesson objective

add lecture button ---------- edit lecture button remove lecture button

lesson parameters name

title

description

lecture type dropdown --- quiz article or video ----- on

selecting quiz or article or video can able to add quiz , article or video.

quiz parameters multiple question -- add question button edit question button remove question button

question --- what is your name ------

no of option = if 3 given , then 3 option , textbox and checkbox must be created

like option1 answer1 iscorrect1 and so on.

Video parameters - URL , provider , length and some more.

article provider - url , provider , length and more.

in course there can be multiple lessons and in each lessons there can be multiple lectures

each lecture will be of type quiz /article or video.....

in one quiz there can be multiple question of either multiple choice answers , single answer , true false answer or

free text box answer.

course -->> les1 lec1 lec2 lec3

les2 lec1 lec2 lec3

les 3

lesson-->> lecture -->>> 3 types now.... quiz , article or video