A couple of screenshots from the schedule settings would help a bit more.
What you want to see is not showing in the schedule total? Are you using "Merge elements" for the schedule?
From what I can understand, what the schedule shows is correct, because tabulated data will be separated when one of the scheduled items differs from the others in any of the scheduled data. Archicad reads the object's parameters and interprets that there are two objects with no_bay=9 and one with no_bay=10, so it won't merge those.
Do you have the sum function activated for those parameters (quantity and no_bay)? It should give you what you need.
Let's begin by saying that I don't see how to get what you want the way you want it. Like I said, in my experience, AC will look at the parameter values and schedule accordingly. For the display parking, you have two objects whose "no_bay" parameter has different values. They won't merge. Another way to understand this is to see those no_bay values as letters or colors. Let's say the ones with 4 bays are "red", and the one with 5 is "blue". For Customer parking you have two reds, for display you have one red and one blue, so they are not the same.
Another thing to note is that the schedule is misleading. Add up the numbers and you don't get 17, you get 13.
I've had this problem before. This was one of the things why I developed the parking object I posted some time ago (look for it in the forums, or PM me). It can solve this issue by placing two objects, one for display parking and another for customer parking.
There are options.
1. Make separate schedules: one for display parking, one for customer parking, one for both. Place them on a layout and arrange them so only the parts you need show up(the totals). Be sure to set the anchor at the bottom right, so if you add or change anything and new values are placed in the schedule, you will still see the total where you placed it.
2. Place something else that you can count that you could assign a property, i.e. a fill that has an ID of "display" and "customer" that you place in a hidden layer, and use that to create the count schedule.
There may be other ways, but I've learned my lesson with this after a lot of workarounds based on the last option. I learned to NOT use parking objects that you can stretch and give you several parking bays in a single object.
The real trick is to use a single object for each parking bay. Whether it is a fill, an object, a slab, or anything. With AC multiply options, you can place them as fast as a stretchy object, and you can assign a layer, ID, property, etc, to each of them. I ended up creating an object for a single parking bay and control all of the placed objects using library globals. Works like a charm!