dropdown menu in sharepoint

Hello,

My question regarding columns. For example I have Column lets say: Activity 1, which has drop down menu. From drop down menu I enter neccerary information to my Activity 1 column.

Next step, I need to figure out how to add my next column Activity 2.

In other words, while editing if I enter information to Activity 1 column, Activity 2 should appear or activated beneath Activity 1 column. If I don't enter information, so I will have only Activity 1 column.

Should I use some formula or there is another way to do so?

Thanks a lot.