This is several years after the question was asked. But incase someone comes looking for the answer. I have not been able to find a way to search for a property with the primary bedroom down. But if you scroll down the listing, it should be listed as what floor the bedroom is on.
Hello Arege! Yes, Realtors through their MLS system have hundreds of ways to customize their searches for their clients. I have had plenty of clients that look for a bedroom down as a guest bedroom or to be used for someone with disabilities. Of course, these would be in 2 or more story homes only. On the public version of HAR.com, it appears there is NOT a way to search for a bedroom down. Even more of a reason to hire a seasoned Realtor like myself that can guild you through the process and set up custom searches to eliminate the homes you don't want and bring to the front those you wish to see. Call if we can assist.
Yes, a Realtor can go in and search that for you. I do not see that option for a consumer to search for a bedroom downstairs on HAR. However, and this is a big however, there may be one or more bedrooms downstairs, but if the listing agent did not indicate that, then you do not know without viewing the house or calling and checking.