The byte swapping editor of a device is at the device level.
The button 
opens the Byte order window:
That window contains all of data types, for which byte order can be set. The default is the most common sequences of bytes:
2-byte - int16-uint16 - high byte first
4-byte - int32, uint32, float - high word first
8-byte - double - high double word first
Note. There are the following exceptions: 4-byte numbers (int32, uint32, float) in controllers with Codesys 2 (Owen, Wago, Beckhoff and others) - high byte first.
A byte order configured at the device level is applied to all tags with Device byte order = TRUE of that device. If Device byte order = FALSE, the extra setting Byte order becomes available in the tag, and the byte order can be configured for the tag individually (see The Byte Swapping Editor of a Tag).
Using Group Operations, you can switch off individual byte order for tags, and switch on inheritance of the device byte order.