There is no way to control the ZigBee routing of the majority of consumer ZigBee smart home devices, including Xiaomi / Aqara devices. A ZigBee mesh network allows devices to decide their routing based on signal strength, number of hops, etc. The routing can even change after a device has been paired, multiple times, especially if it has been moved after being paired.
However, from my own experience and reports from users, Xiaomi / Aqara devices are stubborn to change their routing, so you could try re-pairing your 2nd Xiaomi socket even further than 12m from your hub, but near the 1st socket, with the hopes that the 2nd socket will route via the 1st instead of directly to the hub. Then quickly unplug the 2nd socket, and re-plug it into the location where you want to use it.
The only problem with this and any other solution to try to “trick” devices into a certain routing path is that there are no tools to discover the routing besides using an XBee ZigBee module.This thread focuses the use of XBee modules as routers to improve a mesh network, but there’s also discussion about their use in displaying a map of all devices on a ZigBee network.