wp_query args adding muitiple tax_querys

You could use IF conditions to add the parameters,

$args = array(
'post_type'      => get_post_type(),
'orderby'        => 'menu_order',
'order'          =>  'ASC',
'posts_per_page' => -1,
'no_found_rows'  => true,
'tax_query' => array(),
);

if(condition){
    $args['tax_query'] = array(
        'relation' => 'AND',
        array(
            'taxonomy' => 'product_category',
            'field'    => 'slug',
            'terms'    => array($category->slug), //Supply the current product_category terms
        ),
        array(
            'taxonomy' => 'product_locations',
            'field'    => 'slug',
            'terms'    => array($current_location), //Add the product_locations term
            'operator' => 'IN',
        ),
    ),
}
else{
     $args['tax_query'] = array(
        array(
            'taxonomy' => 'product_category',
            'field'    => 'slug',
            'terms'    => array($category->slug), //Supply the current product_category terms
        ),
     );
}