Auto Grouping Based On Cell Value?

I'm building a sales tracking spreadsheet and need to find a way to auto group certain rows based on their cell value. In my tracker I'd like to group by company name and be able to collapse it to look at the details.

Here's an example of my starting point and how I'd like the data to look like in the end.

Starting State:
Company Name contact name sales stage Forcast amount
----------------------------------------------------------------------------------------------
Company A david brown contracts 10,000
Company A John Smith Won 20,000
Company A D'Arcy Davis Canceled 10,000
Company B
Company B

Desired State:
Starting State:
Company Name contact name sales stage Forcast amount
----------------------------------------------------------------------------------------------
+Company A 30,000
+Company B