You could do this with a microflow datasource as follows. In my example I used a non persistent Search entity connected to the the address entity.
I created a page with the Search entity as dataview, used a Input attribute and put a reference selector for the association to Address. I then used a microflow as datasource in which I gave the Search object as parameter.
I put an onchange event on the input field and refreshed the search object triggering a new request to the reference selector datasource microflow to refresh it's possibilities. After this you can use the input variable in a xpath to retrieve the values you want with queries like:
[Street = $Search/Input]
The Line attribute is a complete address line in my case which i filled in a before commit with all the values of the other attributes. Opening possiblities to easely implement a generic search on the input. However, it comes with a con and that is that the contains is translated to a ILIKE statement which is not efficient. So the retrieve is inefficient when used against tables with larger set's of data.
I hope you can translate this example to your project.
So in case you want to fire the microflow on every keypress you can use the OnChange Inputbox from the app store:
I hope this answers your question in total.
I tried the OnChange inputbox, however, it seems not working with reference selector? I used it, but the drop down was never updated. I am not sure why.