Out of the box, Magento comes with a functionality of setting up minimum order quantity for a product except for group, configurable and bundle products but sometimes store owners looking to extend this feature remaining products. MageComp has come up with https://magecomp.com/magento-minimum-quantity-for-group-products.html#mce_temp_url# that allows store owners to set minimum order quantity along with custom validation error message for group products.