Header within a Header

[Anonymous]

I am working on some door and window schedules, and I was wondering how to make "sub-headers" within one header like the ones in the attached image. This image is from the default NCS door schedule, and I haven't been able to figure out how to replicate this in my own custom schedules. Thanks!

[Karl Ottenstein]

See attached screenshot. Select the adjacent headers for which you want a common group header and click on "Insert Header Cell Above".