Representing multi layered data in dashboard

I am working on a new component for a B2B dashboard, and I am at an impasse trying to come up with an intuitive way to show this data, and would really appreciate your fresh perspectives.

We have users with multiple groups, and each group can have 5-40 devices. All these devices can detect and throw an alert, which the user can select the threshold for.

(Let's say it is for sound, and the devices can detect anything between 1-15 dB, so the user can enter any number between 1-15 to get an alert, 0 would be no detection. Anything above 6 would be marked as dangerous)

I want a way to display weekly alerts from all groups and devices, but still be able to show the distribution between device's threshold and alert count.

I played around with a pie chart and connected bar chart, where the pie chart can show the distribution of thresholds across devices, and the bar chart can display all alerts as single bars, (y axis being the value of the reading and the x axis is time). The user could click on the pie chart to filter the bar chart but this representation loses the relationship between threshold value and the alert count. (The lower the threshold, the higher the alert count).

This chart represents 5 groups, 89 devices, 420 total alerts. Focused on devices with threshold of 8 which represents 9% of all alerts and 2 % of all devices, but there's no way in this representation to compare these devices with the alerts coming from the devices that set threshold as 6, which represents 69% of devices and 36% of alerts

Easiest way to achieve this would be to take away the option to change the threshold from the user, and set it to 6 for all devices, but that is not something we are willing to give up.