On the right side of the Company Research page, the S&P 500 is the default Starting Universe.
To change the starting universe, click the 
icon and select or upload a portfolio or fund:
The user can now use any portfolio they've uploaded that contains individual stocks as a starting universe. In the screenshot below, a portfolio was uploaded called "Top Holdings", so it now shows as an option for my starting universe.
The user can also search for any fund ticker symbol, and use the holdings of that fund as your starting universe. In the example below, IWB is used to represent the Russell 1000 as the starting universe.