How to trigger inner expansion panel status to panelOpenState = false when toggling outer panels?

Question

I want to close the nested panels with clicking the other outer panel. The solution I tried is: given an id: #child1 and tried to trigger it using click event on header/panel of outer (click)="child1._toggle()" But, it didn't worked. Any Suggestions?

Here is the link to the problem.

Answer 1

Eventually, it worked on stackBlitz. But in my localhost it gives an error "Property 'panelH' doesn't Exist on type 'ExpansionOverviewExample'.

Answer 2

After two days, didn't got any answer from anyone out there. Anyhow, I resolved this matter by altering the step method.

When clicking the outer Expansion or Parent Expansion, I changed the child step to -1. Which opens the -1 indexed panel that isn't there and closes all other by it's default function.