on that page, the items are all inline objects.
1 - DRaw a large HTML item to contain the boxes with effects in in
2 - Click in the box so the cursor is there for typing
3 - Go to Insert>HTML Item
4 - Repeat step 4
5 - Make the width of these boxes the same width as the container HTML item
6 - Use the Transition FX Action to make the HTML box created in step 3 the one which does the triggering to show and hide the HTML box you made in step 4
Repeat this process as many times as you like. You may want to flat each HTML item to the left to get them to appear to be joined to and bottom.