Preparing dependent list using google sheet

So here i want to create a mini wiki like app. Where once a button is clicked .. spinner will give a list.. after selecting one of the name from spinner next list would open... after selecting one of the topic .. a text box will give out the data.

for eg. first Spinner has options 1. aaa, 2.bbb, 3.ccc.

next list view/spinner has options like for if first selection 1 then ddd, eee, fff if selection 2 then ppp,qqq,rrr if selection 3 then jjj,kkk,lll

Now I've made up the format .. only thing is I want to use sheets for the lists.. So i can do addition and deletion to the list.

I could make till first part where first spinner options were taken from sheet. for second dependent list I am not able to get the data as per the idea. I am getting error

Please show your relevant blocks and screenshots of your lists on google sheets.

If you download the entire sheet into a table, you can use this technique to traverse it ...