Using WP_Query for a repeatable group

I am using a CMB2 repeatable group called ‘metric’ which is inside my custom ‘product_cpt’. Inside the ‘metric’ group are fields ‘type’ and ‘units’.
Example data would be like:
metric group 1
-Type = “A”
-Units = “1”
metric group 2
-Type = “B”
-Units = “2”

I’m trying to build a query that searches for Type=”A” AND Units=”1″ across all metric groups, and return the products that have a match.

So far I have this but I’m not getting any results:

$meta_query = array('relation' => 'AND');
$meta_query[] = array(
                   'key' => '_product_cpt_metric_type',
                   'value' => 'A'
                    );
                  $meta_query[] = array(
                    'key' => '_product_cpt_metric_units',
                    'value' => "1"
                    );

$args = array(
                    'post_type'  => 'product_cpt'
                    'orderby' => 'title',
                    'order' => 'ASC',
                    'nopaging' => true,
                    'meta_query' => $meta_query
                  );

I think the problem is that the meta keys are wrong. In the db, the meta key is just ‘_product_cpt_metric’ and the value contains info for all groups. But then how do I specifically look for a combo of fields in one of the groups?

This is what the meta_value in the database for the meta_key ‘_product_cpt_metric’ that has a group for type=A,units=1 and type=B,units=2:
a:2:{i:0;a:2:{s:4:”type”;s:1:”A”;s:5:”units”;s:1:”1″;}i:1;a:2:{s:4:”type”;s:1:”B”;s:5:”units”;s:1:”2″;}}