Lots of airports have multiple security checks. For example, Jakarta has their preliminary security check at the entrance to the airport, before the check-in desks. As at KLIA, the thorough security check is at the gates.

This approach means that not all flights receive the same security checks. On domestic flights within Malaysia, there are no restrictions (AFAIK) on liquids. (I'll avoid off-topic commentary here and simply say that this is perfectly acceptable to me and to most of the world.) On international flights, there are usually limits on liquids and other items, but because security is performed at the gate, this can vary based on the destination.