Play multiple Cinema Trailer pre-rolls?

I have 2 categories of pre-rolls, Dolby Trailers and Silence Policies. I’d like to be able to randomly select 1 from each category to be played making a total of 2 to play prior to the film. I have tried various strings in the “Cinema Trailers pre-roll video” field to no avail (i.e. dolby1;dolby2,silence1;silence2 <- note the use of ; and ,). I assume this is not supported - and I know its an “out there” request, but - might something like this be possible one day?

Early 2021 clean-up: duplicate