Uncode: Create Custom Search Shortcode
Uncode has a search module that you could use, but what if you only want to search for a certain post type?

Without any plugins you could create an easy search form inside a shortcode.
Here is an example:
function filter_jobs( $search ) {
$search = '
<form role="search" method="get" id="searchform" action="' . home_url( '/' ) . '" >
<div class="search-container-inner">
<label class="screen-reader-text" for="s">' . __('Search for:') . '</label>
<input class="search-field form-fluid form-xl" type="text" value="' . get_search_query() . '" name="s" id="s" placeholder="keresés" />
<input type="hidden" name="post_type" value="career" />
<i class="fa fa-search3"></i>
</div>
</form>';
return $search;
}
add_shortcode('filter-jobs', 'filter_jobs');
Here is added the Shortcode [filter-jobs]. It also has the correct classes from Uncode, so it looks like this:

To search for a certain post type only, take a closer look to the:
<input type="hidden" name="post_type" value="career" />
Here the value determents the post type search.