I’ve been trying to do something similar. I needed to pull list of category Names and slugs and use them to populate a News feed. I’m sure this is probably not the best way to do it but it worked for me.
//vars
$terms = get_sub_field('filter_news_feed');
//set variables for the category slug and category name
$output = "";
$nameOutput = "";
//Loop throuh each item in the array and assign the slug and name values to their variables
foreach( $terms as $term ):
$output.= $term->slug . ', ';
$nameOutput.= $term->name . ', ';
endforeach;
//trim the last , and space ' ' off of the list
$trimOutput = rtrim($output,', ');
//trim the last , and space ' ' off of the list
$trimNameOutput = rtrim($nameOutput,', ');
and then to load it into the array:
$args = array(
'post_type' => 'post',
'post_parent' => 0,
'posts_per_page' => 4,
'order' => 'DSC',
);
//adding 'category_name' => 'slug, slug, slug, etc'; to args array
$args['category_name'] = $trimOutput;
Hope that helps….