Segments are saved filters that allow you to quickly revisit specific views of your Inbox that show only relevant threads.
To create a new segment:
Click +Filter at the top of the Inbox.
Select the filter category
Select the applicable value that you want to be displayed (for all other categories aside from 'Currently Staying').
If you skip this step, the filter will remain visible but will not be applied until you click on it again and select a value. A filter in this limbo state will be colored yellow.
Click on +Filter again if you want to add another filter. There is no limit to the number of filters you can apply at one time.
Give this segment a name. Emojis are allowed and encouraged!
Click Save. The new segment will appear on the left sidebar under Saved Segments.