With the base multi account container extension https://addons.mozilla.org/en-US/firefox/addon/multi-account... you can right click in any page and have it remember the container for that domain. For example you open abc.com in container "Personal" once, then you can tell it do remember to use that container whenever you go to abc.com.

The Conex extension https://github.com/kesselborn/conex goes beyond by (optionally) prompting you for which container you want. The best part of this extension is that it lets you hide tabs that aren't in the same container, effectively giving you tab groups based on container. Once you get used to it, you won't want to go back to having 80 tabs displayed at once.

In addition