I am using SharePoint Online. I have a site with 2 basic lists. I am now creating a sort of "portal" page for users of the site to get information from the lists. Instead of displaying the entire lists on the portal page, i want each list to be displayed as a dropdown menu. If a user selects an item in the dropdown list, then it should then display that item from that list. This will be for displaying information only - no editing would be done via the portal. Is there any way to do this either OOB or via SPD (i am not a developer).
Unfortunately your requirement need to be done by coding so there is no way to get lists and insert them in dropdown and get listitems from specified list without code.