<form method="post" action="/page/?foo=ABC">
<select name="foo">
<option value="ABC">ABC</option>
<option value="DEF">DEF</option>
</select>
<select name="bar">
<option value="GHI">GHI</option>
<option value="JKL">JKL</option>
</select>
<input id="search" type="text" placeholder="Search">
<input type="submit" value="">
</form>
I have the above form on a WordPress site. If I go to /page/?foo=ABC, this page shows me everything as it should where foo = ABC.
What do I need to set the action as to get the option from the select?
Your form needs to use GET instead of POST:
Then then all the inputs will be appended to the URL in the manner you seek.
As Marc B said in the comments, use