TrafficLight panel to link into another dashboard forwarding dashboard variable

Hi There !
First post here, so far I have been able to setup a very nice test environment dashboard all by myself !
Kudos for the user friendliness and extensive documentation.

First hiccup though.

From a Traffic Light Pannel, I keep track of various system statuses per environments (so far 2 environment are monitored : TEST, UAT)

Traffic lights point at the detailed status of the underlying monitored system (another dashboard)

Since on the overview dashboard, the environment variable is already set, I would like that the link on the traffic light points at the detailed system environment dashboard in the same environment, so the user would not have to change the value of the environment variable himself.

In the url I have been using htpp:/…&var-environment=$environment
but $environment is not evaluated to its current value.

What am I doing wrong here ?

Grafana version : 6.2.1