In a form or input field for editing or creating a record within a database collection, fields with multiple relationships require the user to be able to select multiple options.
Absolutely imperative to have this functionality.
I was actually shocked when I discovered that Adalo doesn’t have this implemented yet.
The multi-select combo box that’s actually in use right now for the Adalo Database GUI is perfect.
Please. Please. Pretty Please! 
Can we make it so we can edit the border color and also the rounding? It don’t look right with the design I use.