Show Calendar As Resource
"Show as resource" lets you treat a whole calendar as if its contents were all linked to one of your resources. This is a great way to put shared calendars in the correct rows/columns on your scheduling views.
Details & Example
While your FileMaker events likely have a "resource" field in your table, your Google calendars often do not. In fact, you may have many Google calendars being shared with you and each one represents the availability of a particular person. For example, it's common that your teammates or volunteers may share their personal calendars with you (sometimes blocking out the event details) so you don't schedule conflicts with their other commitments.
In cases like these, you'll want to take their whole Google calendar and treat all the events in it as if they were for one resource: showing "Amy'sGoogle Calendar" in the "Amy Browm" resource column. That way when your filter for Amy Brown, or check out Amy's availability on the scheduling views, you'll see her shared Google events in the same column/row as her FileMaker events.