This is not possible at the moment, and I’m unfortunately not available for customization work. I’m planning to make this possible in a future release, just not sure in which update I will include this option.
If you know how to code then you would have to do it like this.
Load a custom template with this filter.
In the /frontend/templates/default.php you see this code:
if ( $wpsl_settings['category_dropdown'] ) {
$output .= $this->create_category_filter();
}
Replace that function with a custom one that outputs checkboxes instead of a dropdown list.
You can find the create_category_filter() in the class-frontend.php, and use it as an starting point.
Next you grab the values from the selected checkboxes in the makeAjaxRequest function in the /js/wpsl-gmap.js ( the wpsl-gmap.min.js is used in the frontend, so you do have to minify the file after making changes on a site like https://javascript-minifier.com/ ), and include them in the ajax request.
The last step is to modify the sql query so that it searches for multiple terms, you can do this with this filter.
I’m planning to add support in the wpsl-gmap.js so it automatically includes data from custom checkboxes/dropdowns. So if an extra dropdown is added, or in this case extra checkboxes, then the selected value is automatically included in the ajax request.
The same with the sql query. Now it only searches for a single term, but support for multiple terms will come in a future update. This will make it much easier to do what you want, without having to modify several core files.
