Hello...
I don't know if the title makes sense or not, but here is my goal. I have a dispatch sheet which I filter to find the buses which are on the road. It looks for:Coach#, Driver, DepartDateTime, ReturnDateTime
I VSTACK that filter with another that looks for buses that are in the shop. It looks for:Coach#, Reason, StartDateTime, EndDateTime
Together these two together give all the Coaches that are out. The second column gives either the driver or reason the coach is in the shop. The third and fourth columns show the datetimes for these, and I use that to provide for a calendar view of dates when buses are not available for one of the two reasons (already on the road, and in the shop).
It works great, thanks to help from this forum in past questions. 
The problem I just encountered is that I now have a reason for which to recall which data comes from which stack. I would like to add a field to the group that says either road or shop. But how to do it. I have floundered at ways to do so within the main formula, which is complicated, as follows:
==LET(x,VSTACK(SORT(FILTER(FILTER(BkgBusMapData,(E1<=BkgTIn)*(E2>=BkgTOut)*(BkgCancel=0),{"¬","","","","",""}),{1,1,0,1,1,0}),4),FILTER(OOSShopData,(E1<=OOSBackfrmShop)*(E2>=OOSOut2Shop),{"¬","","",""})),FILTER(x,TAKE(x,,1)<>"¬"))
I am willing to receive ideas on putting something in there... but after failing to find a resolution I finally decided on another approach. Unfortunately I need help on this as well.
My second approach was to create a column that uses some of the filtered spill data to give the needed data.
I am attaching a picture with the columns. My original, working formula, is in the first column and it returns the background colors of the buses on the busmap using the equipment table. It spills and works fine. A5 by the way can never be blank, but adding that If made the difference between the column spilling and not.
So I added the last column to compare the reasons for bus in shop to the list of available reasons: ListFShopR. Any bus on the road will have a driver, not a shop reason, in that field... so it will then evaluate as FALSE. As you can see, the 4 buses in the shop evaluate as True. That line also works, but it doesn't spill, and F5# of course doesn't work. I tried other methods to make it spill, but it makes the formula error. So I entered the appropriate formula into each row, and it works.
My final goal is to have all buses in the shop for maintenance or inspections to show on the busmap calendar as red... color 192. So the combination uses an IF formula to attach the ideas into one formula. BUT it returns the same values as the first formula. I do not understand why.

Thanks again for any help on either side, though if I had my preference, I would choose the second method to solve.
GaryVSTACK issue.jpg