ngx-treeview : Tree view drop down should show only the parents and children of passed value.

Hi,

• https://leovo2708.github.io/ngx-treeview/#/template
• https://github.com/leovo2708/ngx-treeview/tree/master/src/demo/dropdown-treeview-select

I have drop down tree view as follows:

I want to show only the parents and children of passed value.
For example if I pass value as Hubli then it should show as follows:

If I type filter text box then it is working properly but I want to do this with code. I tried using onFilterChange() and also with filteredChange event emitter but not getting result as expected.

How to achieve this?