How Do You Manually Buy Shares For Investment Fund?

I'm looking under "Shares" / "Your Share Portfolio"

If I scroll down to "Investment Fund Portfolio," then I am able to buy/sell shares of corporations for which the IF already owns shares. The "Share Portfolio for investment fund" lets you click a box next to the listed corporations, then specify "Order Quantity" or "Offer Quantity." But how do you buy shares of a corporation for which you don't already own any shares?

I feel like I must be missing something obvious because other posts in the forums talk about using a country's investment fund to purchase a percentage of state corporations that are going public.

If I look up the corporation on the share market and click buy, the game assumes I want the Country, not the investment fund, to buy the shares...

Or is it just not possible for Country X Investment Fund to purchase shares of a public corporation also located in Country X?

The only shares your investment funds can buy are of corps not located in your country.

If you have more than one country, then the investment funds of one of your countries can buy shares of corps located in any other of your countries. Your investment funds also can buy shares of corps located in countries that you don't own.

Thanks!