Modifying search Criteria

I’m using the Jobify theme, w/ WP job manager plugin. I’m attempting to modify / add search criteria to the job search widget. I was able to add a drop down, that passes in correct information and outputs the correct queried arguments but its not actually doing any filtering. I could be misinterpreting the example provided by WP Job Manager, and hooking it in incorrectly. Any advice would be much appreciated.

Thanks in advance!

WPJM example: http://wpjobmanager.com/document/tutorial-adding-a-salary-field-for-jobs/#section-4
myGist: https://gist.github.com/cmehrabian/a5d1085061b1e0d17c48

add_action( 'job_manager_job_filters_search_jobs_end', 'filter_by_school_field' );

function filter_by_school_field() {
	?>
	<div class="search_categories">
		<label for="search_categories"><?php _e( 'Salary', 'wp-job-manager' ); ?></label>
		<select name="filter_by_school" class="job-manager-filter">
			<option value=""><?php _e( 'Any School', 'wp-job-manager' ); ?></option>
			<option value="cabrillo"><?php _e( 'Cabrillo', 'wp-job-manager' ); ?></option>
			<option value="csumb"><?php _e( 'CSUMB', 'wp-job-manager' ); ?></option>
			<option value="hartnell"><?php _e( 'Hartnell', 'wp-job-manager' ); ?></option>
			<option value="miis"><?php _e( 'MIIS', 'wp-job-manager' ); ?></option>
			<option value="mpc"><?php _e( 'MPC', 'wp-job-manager' ); ?></option>
			<option value="ucsc"><?php _e( 'UCSC', 'wp-job-manager' ); ?></option>
		</select>
	</div>
	<?php
}
/**
 * This code gets your posted field and modifies the job search query
 */
add_filter( 'job_manager_get_listings', 'filter_by_school_field_query_args', 10, 2 );
function filter_by_school_field_query_args( $query_args, $args ) {
	if ( isset( $_POST['form_data'] ) ) {
		parse_str( $_POST['form_data'], $form_data );
		if ( ! empty( $form_data['filter_by_school'] ) ) {
			$selected_range = sanitize_text_field( $form_data['filter_by_school'] );
			switch ( $selected_range ) {
				case 'cabrillo' :
					$query_args['meta_query'][] = array(
						'key'     => '_affiliated_school',
						'value'   => 'cabrillo',
						'compare' => '='
					);
				break;
				case 'csumb' :
					$query_args['meta_query'][] = array(
						'key'     => '_affiliated_school',
						'value'   => 'csumb',
						'compare' => '='
					);
				break;
				case 'hartnell' :
					$query_args['meta_query'][] = array(
						'key'     => '_affiliated_school',
						'value'   => 'hartnell',
						'compare' => '='
					);
				break;
				case 'miis' :
					$query_args['meta_query'][] = array(
						'key'     => '_affiliated_school',
						'value'   => 'miis',
						'compare' => '='
					);
				break;
				case 'mpc' :
					$query_args['meta_query'][] = array(
						'key'     => '_affiliated_school',
						'value'   => 'mpc',
						'compare' => '='
					);
				break;
				case 'ucsc' :
					$query_args['meta_query'][] = array(
						'key'     => '_affiliated_school',
						'value'   => 'ucsc',
						'compare' => '='
					);
				break;
				// default :
				// 	$query_args['meta_query'][] = array(
				// 		'key'     => 'affiliated_school',
				// 		'value'   => array_map( 'absint', explode( '-', $selected_range ) ),
				// 		'compare' => 'BETWEEN',
				// 		'type'    => 'NUMERIC'
				// 	);
				// break;
			}
			// This will show the 'reset' link
			add_filter( 'job_manager_get_listings_custom_filter', '__return_true' );
		}
	}
	return $query_args;
}

https://wordpress.org/plugins/wp-job-manager/