Try googling for "mendix elastic search" there are some good example videos and blogs available

You could use the 3rd party module "Global Search" from marketplace

The Global Search module provides advanced search capabilities based on Lucene Search for your Mendix app. More specifically, this module allows you to search through multiple entities and attributes with just one query.

- Advanced lucene search: search by using the Lucene Query language.

- Simple and advanced indexing: Simple indexing indexes the mendix entity. Advanced indexing used a json structure to index the entity. This way, you can fully customize what you want to index for each searchable object, including searching over association for example.

- Making entities searchable by creating specializations of GlobalSearch.SearchableObject. No more runtime configuration needed, everything can be set-up during development.