How do I search a movie from a specific service provider?

Hello. Can someone please let me know if there’s a way to limit a search to a specific service / content provider? For example, let’s say I’d like to search all movies & shows on Showtime, released after 1990, with an average IMDB user rating of 6.5 or higher. I know there’s a way to do a custom search like this, but I don’t see any way to limit the search to a service provider (like Showtime for example).

I notice there’s a way to select from a list of service providers elsewhere in the app, but it’s separate from the custom search option described above. I also found this feature confusing, because the providers I select from don’t seem to remain after selected.

For example, once I select my preferred providers, I notice it shows them amongst a series of tags in horizontal view, yet only some of them are shown, and then if I click on one of them it oddly omits it from the list. I’m confused why clicking on a tag removes it… why not all of the selected providers ever show… why there’s apparently no way to limit a search based on a specific service provider… why certainly providers such as Shutter aren’t available... & why certain movie titles that have different names in the US & overseas don’t show up when searched for (can’t the database recognize both names?). 

One last thing… (to the IMDB team)… you should prevent this message submission page from deleting unfinished comments when a user switches over to another app and returns. I had to re-type this entire comment simply because I quickly switched over to the IMDB app from this IMDB browser page (so that I could provide more specific details to my questions), yet as soon as I came back here, my un-submitted comment had been deleted. So to avoid this from occurring again I’m basing the details of my above questions off of memory.