What is the best way to differentiate the path in funnel analysis?

I have one button, and one dropdown on the same page. 

There will be 3 events for each:

1. button shown → button clicked → target page
2. dropdown shown → dropdown clicked → target page

My question is,
Q1.

what’s the granularity of time interval amplitude is using?

Let’s say, if the granularity is 1 minute, within 1 minute

button shown → dropdown shown → button clicked → dropdown clicked → target page

Since all the events happen in one minute, how to tell which scenarios (button or dropdown) completed the flow?

Thanks.