Have you tried applying a filter to the oData model, you might need manually set the filter in the suggest event??
https://sapui5.hana.ondemand.com/sdk/#docs/guide/BindingAggregations.html
Not sure how well it will perform if you have to make a new request on live change, but this it's your only option if you're not returning all the results to the client.
Regards,
Jason