Overall, Dimensions allow you to distribute your data (e.g., based on a date, product ID, acquisition channel, etc).
There are two types of Dimensions: Dimensions “from API” are those which are already available in your Data Source whereas Custom Dimensions can be created directly in Reeport, off the top of one or several Data Sources.
If you want to build a Custom Dimension called “Time of the Day” where “Morning” is from 7AM to 12PM, “Lunch Time” is from 12PM to 2PM, and “Afternoon” is from 2PM to 6PM, then you would have to build a Custom Dimension with 3 values (“Morning”, “Lunch Time” and “Afternoon”) with the relevant Conditions in order to include the corresponding time slots.
A Custom Dimension can be based on Conditions (“Mobile trafic only” vs. “Desktop + Tablet” filters), Data Sources (“My Google Analytics View #1″ vs.”My Google Analytics View #2”), and Date Ranges (“Current year” vs. “Last year”).
Create a Custom Dimension
Choose “Custom” on the Widget Dimension option
Click on “Select a Custom Dimension”
Click on the “Add one” button
Name your Custom Dimension and your first row
Click on “Add Segment or Filter”, you can also add an Datasource View or/and a Date Range (If no one is added, the custom dimension will be inherited by the data input)
If needed, add other row by clicking on "add row" and hit “Save”