You are unable to select multiple values for Characteristic under selection in the report.
Cloud for Customer
Business By Design
Reproducing the Issue
Go to Business Analytics
Go to Design Report and search for the effected report
Click on the value help of the Characteristic and while making selection, you notice that only one value is allowed at a time
Edit the same report in report wizard and go to step 5 - "Define Variables"
You should see that under "Selection Type" , you have "Single Value" as selected for the same characteristic
Changes need to be done in the "Selection Type" as to "Multiple Value" from "Single Value"
This will allow to select multiple values in the selection of the characteristics under the report
KBA , report selection , single value in selection , AP-RC-ANA , C4C, ByD, Travel: Analytics Tools & Frameworks , How To