Populating hidden items on button click in android

I have 2 buttons one below the other and i have other 4 hidden buttons besides them . I want to unhide 2 of those button when my first button is clicked and organize them exactly below that button while the other 2 buttons should be unhide when 2nd button is clicked exactly below the 2nd bhutton. Now if i place these hidden buttons they will occupy space in between my visible buttons, which i dont want .Is there any way by which i can push my 2nd visible button down and show my 2 of the hidden buttons onclick of 1st visible button.???