I passed by the same issue and I solved it by doing the following:
Let us say you have 3 remote app applications, 2 of them for finance team and 1 for sales team
1. I exported the TSPUB file from my single RDS Host server, From the UAG I added RemoteApp application, pointed to the TSPUB, picked only the 2 Finance Apps. From the Authorization TAB, I unchecked
allow all users and allowed only the Finance OU (AD integrated) or you can add them manually.
2. Again I add another Remote App in the UAG, pointed to the same TSPUB (It gave me a warning since the same RDS Host was used on another RemoteApp but it will work normally), this time picked
the 1 Sales applications. From the Authorization TAB, I unchecked allow all users and allowed only the Sales OU (AD integrated) or you can add them manually.
One other workaround, is to create one RemoteApp and right click on it in the UAG - Duplicate and change your settings.
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