The popular and well-written job board plugin WP Job Manager has a large add-on library. For both itself and add-ons, WP Job Manager provides a variety of search solutions. WP Job Manager Integration will do the work if you want to improve those search fields’ keyword-only functionality.
Simply by turning on WP Job Manager Integration, SearchWP will be given access to manage the keyword search field for both the core of WP Job Manager and the Resume add-on. This plugin just limits the keyword-provided results; all other filters will continue to work as before.