<?php
/**
** change facet1 to the name of your first facet (the facet to check selection)
** facet2 to the name of your second facet (to be disabled)
**/
add_action( 'facetwp_scripts', function() {
?>
<script>
(function($) {
document.addEventListener('facetwp-loaded', function() {
if ( 'undefined' !== typeof FWP.facets['facet1'] && FWP.facets['facet1'].length > 0 ) {
$( '.facetwp-facet-facet2 select' ).attr('disabled', 'disabled');
}
});
})(fUtil);
</script>
<?php
}, 100 );