A segment is a dynamic saved set of criteria. After it’s been saved, if new or different records meet the set of criteria, the segment will be automatically updated. For example, if you have a saved segment of registered voters, and more people register to vote, the newly registered voters will appear in the results of the segment.
You can build a segment with many tags and fields selected. Click on the Audience > Segments. Refine your segment as much as you would like with any combination of criteria from the left column. Each time you select new criteria, your results will automatically filter.
Documentation on each criterion in the segment tool can be found here. This is what your screen will look like in the segment tool:
To refine your data by specific tags or custom attributes, select the "Custom" tab on the lower left-hand side of the segmenting tool. You will then have the option to select your desired custom attribute.
If you would like to refine your data by multiple custom radios, custom checkboxes, custom texts, and custom tags you will need to do this by clicking in Power Editor.
Power Editor allows you to refine your segment by using the AND OR NOT option. For example, if you wanted to know what users were Facebook OR Twitter users you could do that in this function. You can switch back and forth between segmenting and power editor at any time.
If you want to segment on multiple data points, click on Save Selections before selecting your second or third criteria.