Wondering how to create this design in bar chart

Dear Auther,

I have this design

It has three main features:
1. Stacked Bars Design : I think already implemented.
2. Cross Line Selection Indicator,, that will be visible when I select a bar.
3. Finally a line over the bar indicated another bar value crossing the bar ,, the green on in the following photo,,

Any advise on how to implement that.

Thanks

Start by reviewing the existing stacked bar chart support in fl_chart and compare it with the two screenshots in the issue. The issue names no files, tests, or entry points and asks for implementation advice; a defined change, acceptance criteria, and validation steps would be needed before work is considered done.

Written by the indexing model from the issue text.