Dear Oliver,
what you are looking for is a kind of 2D list, grid or table view. We plan to extend the Mosaic framework by new list components covering exactly such application cases. Actually, you can implement such behaviour by using the already existing Vertical List. For this purpose you use the Vertical List items as container for the ebedded particular items.
Assuming, you want up to 4 items being displayed side by side, then you arrange 4 regular items side by side within a single Vertical List item. In the OnLoadItem slot method, when the Vertical List item is loaded, you load the content of the 4 embedded items.
To demonstrate this approach, I have prepared a small example. I hope it helps you further:
2D-list example
Best regards
Paul