Although I think I understand what you are trying to achieve, I think you are asking for a potential problem. The BOM as you have attached, is functioning as intended. It shows that there are 1 of each part needed to build the next higher assy and that there are 2 higher-level assemblies needed to build your main assy consisting of 2 tray assy's. What you are looking for is a "shortcut" that could cause a problem. If the qty of the bottom 2 parts was "2", it would be easy to order 2 for each of the next-higher assemblies.
You may want to try clicking the BOM option to show parts only to achieve some of what you are hoping for. This breaks out individual parts from their sub-assy's and shows individual part quantities. It will not show the subassy levels.
Jeff is right. The BOM is doing what it is supposed to be doing.
An alternative might be to do a parts only BOM of create a couple of configurations representing what you are
trying to show and show each of the configs in the BOM.