Hi @boybawang thank you for answering,
Here is the website where the plugin is installed oneclickonejob.com and if you search something you will notice that Jobs2Careers jobs will be displayed at the bottom not mixed or at the top ( I want to be mixed if possible ).
The temple search works like this:
<form method="get" action="<?php echo esc_url( home_url( '/' ) )?>">
<div class="search-box">
<input type="search" title="<?php echo esc_attr_x( 'Search for:', 'label','injob' ) ?>" value="<?php echo get_search_query() ?>" name="s" placeholder="<?php echo esc_attr_x( 'Enter your keywords', 'placeholder','injob' );?>" class="top-search">
<img alt="" src="<?php echo esc_url(get_template_directory_uri())?>/assets/images/search.png" class="sub-search">
</div>
</form>