I use Google Calendar for work, and I often need to check certain groups of people's calendars for availability when scheduling things. Is there a way to group a few individuals' calendars into a group like "research team" and group another selection of people into another group like "product team" so that I can show / hide that combination of people's calendars with a single click?
Google Calendar doesn't include that as a feature.
One solution could be to use the embed calendar customization tool but this will require to embed the calendar on a web page. For details see Add a Google calendar to your website
Another solution could be to use a user-script. I didn't tried this yet.
Even though it is true that Google Calendar hasn't offered the feature of grouping calendars as of yet, there is an app that can do the job. I highly recommend the app "Business Calendar 2" by Appgenix Software. This app allows a unified space for Google and Outlook calendars (and maybe more?).
But anyway, to the juicy part! It does allow you to group calendars. After the group is created and the calendars for the group are chosen, it can add a button down below your calendar(s) to toggle the group and/or individual calendars of your choosing.
So far, it's the only way I've found to do this.