Get ACF (Advanced Custom Field) field groups with their fields for a given custom post type. i.e. where the ACF location rule is "post_type == cpt".

acf5_get_acf_field_groups_by_cpt.php

/**      
 * Returns an array of field groups with fields for the passed CPT, where field group ACF location rule of "post_type == CPT" exists.
 *  - each field group points at an array of its fields, in turn pointed at an array of that field's detailed information:
 *    - array of info for each field [ ID, key, label, name, type, menu_order, instructions, required, id, class, conditional_logic[array()], etc. ]
 *  
 * @since    1.0.0      
*/
function get_acf_field_groups_by_cpt($cpt) {
  // need to create cache or transient for this data?
	
  $result = array();
  $acf_field_groups = acf_get_field_groups();
  foreach($acf_field_groups as $acf_field_group) {
    foreach($acf_field_group['location'] as $group_locations) {
      foreach($group_locations as $rule) {

          if($rule['param'] == 'post_type' && $rule['operator'] == '==' && $rule['value'] == $cpt) {
          
            $result[] = acf_get_fields( $acf_field_group );
                        
          }

      }
      
    }
      
  }
  
  return $result;
}

get_acf_field_groups_by_cpt.php

/**      
   * Returns an array of CPT's where an field group ACF location rule of "post_type == CPT" exists.
   *  - each CPT points at an array of its field group IDs, in turn pointed at an array of that field group's:
   *    - meta: field group meta [ id, title, menu_order ]
   *    - fields: array of info for each field [ key, label, name, type, order_no, instructions, required, id, class, conditional_logic[array()], etc. ]
   *  
   * @since    1.0.0      
  */
  public function get_acf_field_groups_by_cpt() {
    // need to create cache or transient for this data?
		
    $result = array();
    $acf_field_group_manager = new acf_field_group();
        $all_field_groups = $acf_field_group_manager->get_field_groups(array());
        foreach($all_field_groups as $field_group) {
          $group_locations = $acf_field_group_manager->get_location( '', $field_group['id'] );
          foreach($group_locations as $group_location_rules) {
            foreach($group_location_rules as $rule) {
              if($rule['param'] == 'post_type' && $rule['operator'] == '==') {
                $result[$rule['value']][$field_group['id']]['meta'] = $field_group; 
                $result[$rule['value']][$field_group['id']]['fields'] = $acf_field_group_manager->get_fields( '', $field_group['id']);           
              }
            }
          }
        }
    
    return $result;
  }

get_cpt_field_groups.php

/*
 * Accepts a CPT strings as input.
 * Returns an array of field group IDs point at an array of their:
 *  - meta: field group meta [ id, title, menu_order ]
 *  - fields: array of info for each field [ key, label, name, type, order_no, instructions, required, id, class, conditional_logic[array()], etc. ]
*/
function get_cpt_field_groups($cpt) {
  $result = array();
  $acf_field_group_manager = new acf_field_group();
      $all_field_groups = $acf_field_group_manager->get_field_groups(array());
      foreach($all_field_groups as $field_group) {
        $group_locations = $acf_field_group_manager->get_location( '', $field_group['id'] );
        foreach($group_locations as $group_location_rules) {
          foreach($group_location_rules as $rule) {
            if($rule['param'] == 'post_type' && $rule['operator'] == '==' && $rule['value'] == $cpt) {              
              $result[$field_group['id']]['meta'] = $field_group;
              $result[$field_group['id']]['fields'] = $acf_field_group_manager->get_fields( '', $field_group['id']);
            }
          }
        }
      }
  return $result;
}